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ISO 32000-1 Document management — Portable document format — Part 1: PDF 1.7 - page 10

NOTE 1

In the case of showing text with the combined filling and stroking text rendering modes, this behaviour is

independent of the text knockout parameter in the graphics state (see “Text Knockout”).

NOTE 2

The purpose of these rules is to avoid having a non-opaque stroke composite with the result of the fill in the

region of overlap, which would produce a double border effect that is usually undesirable. The special case

that applies when the overprint parameter is true is for backward compatibility with the overprinting behavior of

the opaque imaging model. If a desired effect cannot be achieved with a combined filling and stroking operator

or text rendering mode, it can be achieved by specifying the fill and stroke with separate path objects and an

explicit transparency group.

NOTE 3

Overprinting of the stroke over the fill does not work in the second case described previously (although either

the fill or the stroke can still overprint the backdrop). Furthermore, if the overprint graphics state parameter is

true, the results are discontinuous at the transition between equal and unequal values of the stroking and

nonstroking alpha constants. For this reason, it is best not to use overprinting for combined filling and stroking

operations if the stroking and nonstroking alpha constants are being varied independently.

11.7.4.5

Summary of Overprinting Behaviour

Tables 148 and 149 summarize the overprinting and erasing behaviour in the opaque and transparent imaging

models, respectively. Table 148 shows the overprinting rules used in the opaque model, as described in

“Overprint Control”. Table 149 shows the equivalent rules as implemented by the CompatibleOverprint blend

mode in the transparent model. The names OP and OPM in the tables refer to the overprint and overprint mode

parameters of the graphics state.

Table 148 - Overprinting behavior in the opaque imaging model

Effect on colour component

Source colour

Affected colour

space

component

OP false

OP true,

OP true,

OPM 0

OPM 1

DeviceCMYK,

C, M, Y, or K

Paint source

Paint source

Paint source

specified directly,

if ≠ 0.0

not in a sampled

Do not paint if = 0.0

image

Process colorant

Paint source

Paint source

Paint source

other than CMYK

Spot colorant

Paint 0.0

Do not paint

Do not paint

Any process colour

Process colorant

Paint source

Paint source

Paint source

space (including

other cases of

Spot colorant

Paint 0.0

Do not paint

Do not paint

DeviceCMYK)

Separation or

Process colorant

Paint 0.0

Do not paint

Do not paint

DeviceN

Spot colorant

Paint source

Paint source

Paint source

named in source

space

Spot colorant not

Paint 0.0

Do not paint

Do not paint

named in source

space

358

Table 149 - Overprinting behavior in the transparent imaging model

Affected colour

Value of blend function B (c

, c

) expressed as tint

b

s

Source color space

component of

group colour

OP false

OP true,

OP true,

space

OPM 0

OPM 1

DeviceCMYK,

C, M, Y, or K

c_s

c_s

c_s if c_s ≠ 0.0

specified directly,

c_b if c_s = 0.0

not in a sampled

image

Process colour

c_s

c_s

c_s

component other

than CMYK

Spot colorant

c_s (= 0.0)

c_b

c_b

Any process colour

Process colour

c_s

c_s

c_s

space (including

component

other cases of

DeviceCMYK)

Spot colorant

c_s (= 0.0)

c_b

c_b

Separation or

Process colour

c_s (= 0.0)

c_b

c_b

DeviceN

component

Spot colorant

c_s

c_s

c_s

named in source

space

Spot colorant not

c_s (= 0.0)

c_b

c_b

named in source

space

A group (not an

All colour

c_s

c_s

c_s

elementary object)

components

Colour component values are represented in these tables as subtractive tint values because overprinting is

typically applied to subtractive colorants such as inks rather than to additive ones such as phosphors on a

display screen. The CompatibleOverprint blend mode is therefore described as if it took subtractive arguments

and returned subtractive results. In reality, however, CompatibleOverprint (like all blend modes) shall treat

colour components as additive values; subtractive components shall be complemented before and after

application of the blend function.

NOTE 1

This note describes an important difference between Table 148 and Table 149. In Table 148, the process

colour components being discussed are the actual device colorants—the colour components of the output

device’s native colour space (DeviceGray, DeviceRGB, or DeviceCMYK). In Table 149, the process colour

components are those of the group’s colour space, which is not necessarily the same as that of the output

device (and can even be something like CalRGB or ICCBased). For this reason, the process colour

components of the group colour space cannot be treated as if they were spot colours in a Separation or

DeviceN colour space (see

“Spot Colours and Transparency”). This difference between opaque and

transparent overprinting and erasing rules arises only within a transparency group (including the page group, if

its colour space is different from the native colour space of the output device). There is no difference in the

treatment of spot colour components.

NOTE 2

Table 149 has one additional row at the bottom. It applies when painting an object that is a transparency group

rather than an elementary object (fill, stroke, text, image, or shading). As stated in 11.7.3, "Spot Colours and

Transparency," a group is considered to paint all colour components, both process and spot. Colour

components that were not explicitly painted by any object in the group have an additive colour value of 1.0

(subtractive tint 0.0). Since no information is retained about which components were actually painted within the

group, compatible overprinting is not possible in this case; the CompatibleOverprint blend mode reverts to

Normal, with no consideration of the overprint and overprint mode parameters. A transparency-aware

conforming writer can choose a more suitable blend mode, such as Darken, to produce an effect similar to

overprinting.

359

12

Interactive Features

12.1

General

For purposes of the trigger events E (enter), X (exit), D (down), and U (up), the term mouse denotes a generic

pointing device with the following characteristics:

•

A selection button that can be pressed, held down, and released. If there is more than one mouse button,

the selection button is typically the left button.

•

A notion of location—that is, an indication of where on the screen the device is pointing. Location is

typically denoted by a screen cursor.

•

A notion of focus—that is, which element in the document is currently interacting with the with the user. In

many systems, this element is denoted by a blinking caret, a focus rectangle, or a colour change.

This clause describes the PDF features that allow a user to interact with a document on the screen, using the

mouse and keyboard (with the exception of multimedia features, which are described in 13, “Multimedia

Features”):

•

Preference settings to control the way the document is presented on the screen

(12.2,

“Viewer

Preferences”)

•

Navigation facilities for moving through the document in a variety of ways (Sections 12.3, “Document-Level

Navigation” and 12.4, “Page-Level Navigation”)

•

Annotations for adding text notes, sounds, movies, and other ancillary information to the document (12.5,

“Annotations”)

•

Actions that can be triggered by specified events (12.6, “Actions”)

•

Interactive forms for gathering information from the user (12.7, “Interactive Forms”)

•

Digital signatures that authenticate the identity of a user and the validity of the document’s contents (12.8,

“Digital Signatures”)

•

Measurement properties that enable the display of real-world units corresponding to objects on a page

(12.9, “Measurement Properties”)

12.2

Viewer Preferences

The ViewerPreferences entry in a document’s catalogue (see 7.7.2, “Document Catalog”) designates a viewer

preferences dictionary (PDF 1.2) controlling the way the document shall be presented on the screen or in print.

If no such dictionary is specified, conforming readers should behave in accordance with their own current user

preference settings. Table 150 shows the contents of the viewer preferences dictionary.

Table 150 - Entries in a viewer preferences dictionary

Key

Type

Value

HideToolbar

boolean

(Optional) A flag specifying whether to hide the conforming

reader’s tool bars when the document is active. Default value:

false.

HideMenubar

boolean

(Optional) A flag specifying whether to hide the conforming

reader’s menu bar when the document is active. Default value:

false.

362

Table 150 - Entries in a viewer preferences dictionary (continued)

Key

Type

Value

HideWindowUI

boolean

(Optional) A flag specifying whether to hide user interface

elements in the document’s window (such as scroll bars and

navigation controls), leaving only the document’s contents

displayed. Default value: false.

FitWindow

boolean

(Optional) A flag specifying whether to resize the document’s

window to fit the size of the first displayed page. Default value:

false.

CenterWindow

boolean

(Optional) A flag specifying whether to position the document’s

window in the center of the screen. Default value: false.

DisplayDocTitle

boolean

(Optional; PDF 1.4) A flag specifying whether the window’s title

bar should display the document title taken from the Title entry of

the document information dictionary

(see

14.3.3,

“Document

Information Dictionary”). If false, the title bar should instead

display the name of the PDF file containing the document. Default

value: false.

NonFullScreenPageMode

name

(Optional) The document’s page mode, specifying how to display

the document on exiting full-screen mode:

UseNone

Neither document outline nor thumbnail images

visible

UseOutlines Document outline visible

UseThumbs Thumbnail images visible

UseOC

Optional content group panel visible

This entry is meaningful only if the value of the PageMode entry

in the Catalog dictionary

(see 7.7.2,

“Document Catalog”) is

FullScreen; it shall be ignored otherwise. Default value: UseNone.

Direction

name

(Optional; PDF 1.3) The predominant reading order for text:

L2R Left to right

R2L Right to left (including vertical writing systems, such as

Chinese, Japanese, and Korean)

This entry has no direct effect on the document’s contents or page

numbering but may be used to determine the relative positioning

of pages when displayed side by side or printed n-up. Default

value: L2R.

ViewArea

name

(Optional; PDF 1.4) The name of the page boundary representing

the area of a page that shall be displayed when viewing the

document on the screen. The value is the key designating the

relevant page boundary in the page object (see 7.7.3, “Page Tree”

and 14.11.2, “Page Boundaries”). If the specified page boundary

is not defined in the page object, its default value shall be used,

as specified in Table 30. Default value: CropBox.

This entry is intended primarily for use by prepress applications

that interpret or manipulate the page boundaries as described in

14.11.2, “Page Boundaries.”

NOTE 1

Most conforming readers disregard it.

363

Table 150 - Entries in a viewer preferences dictionary (continued)

Key

Type

Value

ViewClip

name

(Optional; PDF 1.4) The name of the page boundary to which the

contents of a page shall be clipped when viewing the document

on the screen. The value is the key designating the relevant page

boundary in the page object (see 7.7.3, “Page Tree” and 14.11.2,

“Page Boundaries”). If the specified page boundary is not defined

in the page object, its default value shall be used, as specified in

Table 30. Default value: CropBox.

This entry is intended primarily for use by prepress applications

that interpret or manipulate the page boundaries as described in

14.11.2, “Page Boundaries.”

NOTE 2

Most conforming readers disregard it.

PrintArea

name

(Optional; PDF 1.4) The name of the page boundary representing

the area of a page that shall be rendered when printing the

document. The value is the key designating the relevant page

boundary in the page object (see 7.7.3, “Page Tree” and 14.11.2,

“Page Boundaries”). If the specified page boundary is not defined

in the page object, its default value shall be used, as specified in

Table 30. Default value: CropBox.

This entry is intended primarily for use by prepress applications

that interpret or manipulate the page boundaries as described in

14.11.2, “Page Boundaries.”

NOTE 3

Most conforming readers disregard it.

PrintClip

name

(Optional; PDF 1.4) The name of the page boundary to which the

contents of a page shall be clipped when printing the document.

The value is the key designating the relevant page boundary in

the page object (see 7.7.3,

“Page Tree” and 14.11.2, “Page

Boundaries”). If the specified page boundary is not defined in the

page object, its default value shall be used, as specified in

Table 30. Default value: CropBox.

This entry is intended primarily for use by prepress applications

that interpret or manipulate the page boundaries as described in

14.11.2, “Page Boundaries.”

NOTE 4

Most conforming readers disregard it.

PrintScaling

name

(Optional; PDF 1.6) The page scaling option that shall be selected

when a print dialog is displayed for this document. Valid values

are None, which indicates no page scaling, and AppDefault, which

indicates the conforming reader’s default print scaling. If this entry

has an unrecognized value, AppDefault shall be used. Default

value: AppDefault.

If the print dialog is suppressed and its parameters are provided

from some other source, this entry nevertheless shall be honored.

Duplex

name

(Optional; PDF 1.7) The paper handling option that shall be used

when printing the file from the print dialog. The following values

are valid:

Simplex

Print single-sided

DuplexFlipShortEdge Duplex and flip on the short edge of the

sheet

DuplexFlipLongEdge Duplex and flip on the long edge of the

sheet

Default value: none

364

Table 150 - Entries in a viewer preferences dictionary (continued)

Key

Type

Value

PickTrayByPDFSize

boolean

(Optional; PDF 1.7) A flag specifying whether the PDF page size

shall be used to select the input paper tray. This setting influences

only the preset values used to populate the print dialog presented

by a conforming reader. If PickTrayByPDFSize is true, the check

box in the print dialog associated with input paper tray shall be

checked.

This setting has no effect on operating systems that do not

provide the ability to pick the input tray by size.

Default value: as defined by the conforming reader

PrintPageRange

array

(Optional; PDF 1.7) The page numbers used to initialize the print

dialog box when the file is printed. The array shall contain an even

number of integers to be interpreted in pairs, with each pair

specifying the first and last pages in a sub-range of pages to be

printed.The first page of the PDF file shall be denoted by 1.

Default value: as defined by the conforming reader

NumCopies

integer

(Optional; PDF 1.7) The number of copies that shall be printed

when the print dialog is opened for this file. Values outside this

range shall be ignored.

Default value: as defined by the conforming reader, but typically 1

12.3

Document-Level Navigation

12.3.1

General

The features described in this sub-clause allow a conforming reader to present the user with an interactive,

global overview of a document in either of two forms:

•

As a hierarchical outline showing the document’s internal structure

•

As a collection of thumbnail images representing the pages of the document in miniature form

Each item in the outline or each thumbnail image may be associated with a corresponding destination in the

document, so that the user can jump directly to the destination by clicking with the mouse.

12.3.2

Destinations

12.3.2.1

General

A destination defines a particular view of a document, consisting of the following items:

•

The page of the document that shall be displayed

•

The location of the document window on that page

•

The magnification (zoom) factor

Destinations may be associated with outline items (see 12.3.3, “Document Outline”), annotations (12.5.6.5,

“Link Annotations”), or actions (12.6.4.2, “Go-To Actions” and 12.6.4.3, “Remote Go-To Actions”). In each case,

the destination specifies the view of the document that shall be presented when the outline item or annotation

is opened or the action is performed. In addition, the optional OpenAction entry in a document’s catalogue

(7.7.2, “Document Catalog”) may specify a destination that shall be displayed when the document is opened. A

destination may be specified either explicitly by an array of parameters defining its properties or indirectly by

name.

365

12.3.2.2

Explicit Destinations

Table 151 shows the allowed syntactic forms for specifying a destination explicitly in a PDF file. In each case,

page is an indirect reference to a page object (except in a remote go-to action; see 12.6.4.3, “Remote Go-To

Actions”). All coordinate values (left, right, top, and bottom) shall be expressed in the default user space

coordinate system. The page’s bounding box is the smallest rectangle enclosing all of its contents. (If any side

of the bounding box lies outside the page’s crop box, the corresponding side of the crop box shall be used

instead; see 14.11.2, “Page Boundaries,” for further discussion of the crop box.)

No page object can be specified for a destination associated with a remote go-to action (see 12.6.4.3, “Remote

Go-To Actions”) because the destination page is in a different PDF document. In this case, the page parameter

specifies an integer page number

within the remote document instead of a page object in the current

document.

Table 151 - Destination syntax

Syntax

Meaning

[page

/XYZ left top zoom ]

Display the page designated by page, with the coordinates (left, top)

positioned at the upper-left corner of the window and the contents of

the page magnified by the factor zoom. A null value for any of the

parameters left, top, or zoom specifies that the current value of that

parameter shall be retained unchanged. A zoom value of 0 has the

same meaning as a null value.

[page

/Fit ]

Display the page designated by page, with its contents magnified just

enough to fit the entire page within the window both horizontally and

vertically. If the required horizontal and vertical magnification factors

are different, use the smaller of the two, centering the page within the

window in the other dimension.

[page

/FitH top ]

Display the page designated by page, with the vertical coordinate top

positioned at the top edge of the window and the contents of the page

magnified just enough to fit the entire width of the page within the

window. A null value for top specifies that the current value of that

parameter shall be retained unchanged.

[page

/FitV left ]

Display the page designated by page, with the horizontal coordinate

left positioned at the left edge of the window and the contents of the

page magnified just enough to fit the entire height of the page within

the window. A null value for left specifies that the current value of that

parameter shall be retained unchanged.

[page

/FitR left bottom right top ]

Display the page designated by page, with its contents magnified just

enough to fit the rectangle specified by the coordinates left, bottom,

right, and top entirely within the window both horizontally and vertically.

If the required horizontal and vertical magnification factors are

different, use the smaller of the two, centering the rectangle within the

window in the other dimension.

[page

/FitB ]

(PDF 1.1) Display the page designated by page, with its contents

magnified just enough to fit its bounding box entirely within the window

both horizontally and vertically. If the required horizontal and vertical

magnification factors are different, use the smaller of the two,

centering the bounding box within the window in the other dimension.

[page

/FitBH top ]

(PDF 1.1) Display the page designated by page, with the vertical

coordinate top positioned at the top edge of the window and the

contents of the page magnified just enough to fit the entire width of its

bounding box within the window. A null value for top specifies that the

current value of that parameter shall be retained unchanged.

366

Table 151 - Destination syntax (continued)

Syntax

Meaning

[page

/FitBV left ]

(PDF 1.1) Display the page designated by page, with the horizontal

coordinate left positioned at the left edge of the window and the

contents of the page magnified just enough to fit the entire height of its

bounding box within the window. A null value for left specifies that the

current value of that parameter shall be retained unchanged.

12.3.2.3

Named Destinations

Instead of being defined directly with the explicit syntax shown in Table 151, a destination may be referred to

indirectly by means of a name object (PDF 1.1) or a byte string (PDF 1.2). This capability is especially useful

when the destination is located in another PDF document.

NOTE 1

A link to the beginning of Chapter 6 in another document might refer to the destination by a name, such as

Chap6 . begin, instead of by an explicit page number in the other document. Then, the location of the chapter in

the other document could change without invalidating the link. If an annotation or outline item that refers to a

named destination has an associated action, such as a remote go-to action (see 12.6.4.3, “Remote Go-To

Actions”) or a thread action (12.6.4.6, “Thread Actions”), the destination is in the file specified by the action’s F

entry, if any; if there is no F entry, the destination is in the current file.

In PDF 1.1, the correspondence between name objects and destinations shall be defined by the Dests entry in

the document catalogue (see 7.7.2, “Document Catalog”). The value of this entry shall be a dictionary in which

each key is a destination name and the corresponding value is either an array defining the destination, using

the syntax shown in Table 151, or a dictionary with a D entry whose value is such an array.

NOTE 2

The latter form allows additional attributes to be associated with the destination, as well as enabling a go-to

action (see 12.6.4.2, “Go-To Actions”) that shall be used as the target of a named destination.

In PDF 1.2 and later, the correspondence between strings and destinations may alternatively be defined by the

Dests entry in the document’s name dictionary (see 7.7.4, “Name Dictionary”). The value of this entry shall be

a name tree (7.9.6, “Name Trees”) mapping name strings to destinations. (The keys in the name tree may be

treated as text strings for display purposes.) The destination value associated with a key in the name tree may

be either an array or a dictionary, as described in the preceding paragraph.

NOTE 3

The use of strings as destination names is a PDF 1.2 feature. If compatibility with earlier versions of PDF is

required, only name objects may be used to refer to named destinations. A document that supports PDF 1.2

can contain both types. However, if backward compatibility is not a consideration, applications should use the

string form of representation in the Dests name tree.

12.3.3

Document Outline

A PDF document may contain a document outline that the conforming reader may display on the screen,

allowing the user to navigate interactively from one part of the document to another. The outline consists of a

tree-structured hierarchy of outline items (sometimes called bookmarks), which serve as a visual table of

contents to display the document’s structure to the user. The user may interactively open and close individual

items by clicking them with the mouse. When an item is open, its immediate children in the hierarchy shall

become visible on the screen; each child may in turn be open or closed, selectively revealing or hiding further

parts of the hierarchy. When an item is closed, all of its descendants in the hierarchy shall be hidden. Clicking

the text of any visible item activates the item, causing the conforming reader to jump to a destination or trigger

an action associated with the item.

The root of a document’s outline hierarchy is an outline dictionary specified by the Outlines entry in the

document catalogue (see 7.7.2, “Document Catalog”). Table 152 shows the contents of this dictionary. Each

individual outline item within the hierarchy shall be defined by an outline item dictionary (Table 153). The items

at each level of the hierarchy form a linked list, chained together through their Prev and Next entries and

accessed through the First and Last entries in the parent item (or in the outline dictionary in the case of top-

367

level items). When displayed on the screen, the items at a given level shall appear in the order in which they

occur in the linked list.

Table 152 - Entries in the outline dictionary

Key

Type

Value

Type

name

(Optional) The type of PDF object that this dictionary describes; if

present, shall be Outlines for an outline dictionary.

First

dictionary

(Required if there are any open or closed outline entries; shall be an

indirect reference) An outline item dictionary representing the first top-

level item in the outline.

Last

dictionary

(Required if there are any open or closed outline entries; shall be an

indirect reference) An outline item dictionary representing the last top-

level item in the outline.

Count

integer

(Required if the document has any open outline entries) Total number

of visible outline items at all levels of the outline. The value cannot be

negative.

This entry shall be omitted if there are no open outline items.

Table 153 - Entries in an outline item dictionary

Key

Type

Value

Title

text string

(Required) The text that shall be displayed on the screen for this item.

Parent

dictionary

(Required; shall be an indirect reference) The parent of this item in the

outline hierarchy. The parent of a top-level item shall be the outline

dictionary itself.

Prev

dictionary

(Required for all but the first item at each level; shall be an indirect

reference) The previous item at this outline level.

Next

dictionary

(Required for all but the last item at each level; shall be an indirect

reference) The next item at this outline level.

First

dictionary

(Required if the item has any descendants; shall be an indirect

reference) The first of this item’s immediate children in the outline

hierarchy.

Last

dictionary

(Required if the item has any descendants; shall be an indirect

reference) The last of this item’s immediate children in the outline

hierarchy.

Count

integer

(Required if the item has any descendants) If the outline item is open,

Count is the sum of the number of visible descendent outline items at

all levels. The number of visible descendent outline items shall be

determined by the following recursive process:

Step 1. Initialize Count to zero.

Step 2. Add to Count the number of immediate children. During

repetitions of this step, update only the Count of the original

outline item.

Step 3. For each of those immediate children whose Count is

positive and non-zero, repeat steps 2 and 3.

If the outline item is closed, Count is negative and its absolute value is

the number of descendants that would be visible if the outline item

were opened.

368

Table 153 - Entries in an outline item dictionary (continued)

Key

Type

Value

Dest

name,

(Optional; shall not be present if an A entry is present) The destination

byte string, or

that shall be displayed when this item is activated

(see

12.3.2,

array

“Destinations”).

A

dictionary

(Optional; PDF 1.1; shall not be present if a Dest entry is present) The

action that shall be performed when this item is activated (see 12.6,

“Actions”).

SE

dictionary

(Optional; PDF 1.3; shall be an indirect reference) The structure

element to which the item refers (see 14.7.2, “Structure Hierarchy”).

(PDF 1.0) An item may also specify a destination

(Dest)

corresponding to an area of a page where the contents of the

designated structure element are displayed.

C

array

(Optional; PDF 1.4) An array of three numbers in the range 0.0 to 1.0,

representing the components in the DeviceRGB colour space of the

colour that shall be used for the outline entry’s text. Default value:

[0.0

0.0 0.0 ].

F

integer

(Optional; PDF 1.4) A set of flags specifying style characteristics for

displaying the outline item’s text (see Table 154). Default value: 0.

The value of the outline item dictionary’s F entry (PDF 1.4) shall be an integer interpreted as one-bit flags

specifying style characteristics for displaying the item. Bit positions within the flag word are numbered from low-

order to high-order bits, with the lowest-order bit numbered 1. Table 154 shows the meanings of the flags; all

other bits of the integer shall be 0.

Table 154 - Outline item flags

Bit position

Name

Meaning

1

Italic

If set to 1, display the item in italic.

2

Bold

If set to 1, display the item in bold.

EXAMPLE

The following example shows a typical outline dictionary and outline item dictionary. See H.6, “Outline

Hierarchy Example” for an example of a complete outline hierarchy.

21 0 obj

<<

/Count 6

/First

22 0 R

/Last

29 0 R

>>

endobj

22 0 obj

<<

/Title

( Chapter 1 )

/Parent 21 0 R

/Next 26 0 R

/First

23 0 R

/Last

25 0 R

/Count 3

/Dest [ 3 0 R /XYZ 0 792 0 ]

>>

endobj

369

Table 155 describes the entries in a collection dictionary.

Table 155 - Entries in a collection dictionary

Key

Type

Value

Type

name

(Optional) The type of PDF object that this dictionary

describes; if present, shall be Collection for a collection

dictionary.

Schema

dictionary

(Optional) A collection schema dictionary (see Table 156). If

absent, the conforming reader may choose useful defaults

that are known to exist in a file specification dictionary, such

as the file name, file size, and modified date.

D

byte string

(Optional) A string that identifies an entry in the

EmbeddedFiles name tree, determining the document that

shall be initially presented in the user interface. If the D entry

is missing or in error, the initial document shall be the one

that contains the collection dictionary.

View

name

(Optional) The initial view. The following values are valid:

D The collection view shall be presented in details mode,

with all information in the Schema dictionary presented

in a multi-column format. This mode provides the most

information to the user.

T The collection view shall be presented in tile mode, with

each file in the collection denoted by a small icon and a

subset of information from the Schema dictionary. This

mode provides top-level information about the file

attachments to the user.

H The collection view shall be initially hidden, The

conforming reader shall provide means for the user to

view the collection by some explicit action.

Default value: D

Sort

dictionary

(Optional) A collection sort dictionary, which specifies the

order in which items in the collection shall be sorted in the

user interface (see Table 158).

A collection schema dictionary consists of a variable number of individual collection field dictionaries. Each

collection field dictionary has a key chosen by the conforming writer, which shall be used to associate a field

with data in a file specification. Table 156 describes the entries in a collection schema dictionary.

Table 156 - Entries in a collection schema dictionary

Key

Type

Value

Type

name

(Optional) The type of PDF object that this dictionary

describes; if present, shall be CollectionSchema for a

collection schema dictionary.

Other keys

dictionary

(Optional) A collection field dictionary. Each key name is

chosen at the discretion of the conforming writer. The key

name shall be used to identify a corresponding collection

item dictionary referenced from the file specification

dictionary's CI entry (see CI key in Table 44).

371

A collection field dictionary describes the attributes of a particular field in a portable collection, including the

type of data stored in the field and the lookup key used to locate the field data in the file specification dictionary.

Table 157 describes the entries in a collection field dictionary.

Table 157 - Entries in a collection field dictionary

Key

Type

Value

Type

name

(Optional) The type of PDF object that this dictionary describes; if

present, shall be CollectionField for a collection field dictionary.

Subtype

name

(Required) The subtype of collection field or file-related field that this

dictionary describes. This entry identifies the type of data that shall

be stored in the field.

The following values identify the types of fields in the collection item

or collection subitem dictionary:

S A text field. The field data shall be stored as a PDF text string.

D A date field. The field data shall be stored as a PDF date

string.

N A number field. The field data shall be stored as a PDF

number.

The following values identify the types of file-related fields:

F

The field data shall be the file name of the

embedded file stream, as identified by the UF entry

of the file specification, if present; otherwise by the F

entry of the file specification (see Table 44).

Desc

The field data shall be the description of the

embedded file stream, as identified by the Desc

entry in the file specification dictionary

(see

Table 44).

ModDate

The field data shall be the modification date of the

embedded file stream, as identified by the ModDate

entry in the embedded file parameter dictionary (see

Table 46).

CreationDate The field data shall be the creation date of the

embedded file stream, as identified by the

CreationDate entry in the embedded file parameter

dictionary (see Table 46).

Size

The field data shall be the size of the embedded file,

as identified by the Size entry in the embedded file

parameter dictionary (see Table 46).

N

text string

(Required) The textual field name that shall be presented to the user

by the conforming reader.

O

integer

(Optional) The relative order of the field name in the user interface.

Fields shall be sorted by the conforming reader in ascending order.

V

boolean

(Optional) The initial visibility of the field in the user interface.

Default value: true.

E

boolean

(Optional) A flag indicating whether the conforming reader should

provide support for editing the field value. Default value: false.

A collection sort dictionary identifies the fields that shall be used to sort items in the collection. The type of

sorting depends on the type of data:

•

Text strings shall be ordered lexically from smaller to larger, if ascending order is specified.

NOTE 3

Lexical ordering is an implementation dependency for conforming readers.

372

•

Numbers shall be ordered numerically from smaller to larger, if ascending order is specified.

•

Dates shall be ordered from oldest to newest, if ascending order is specified.

Table 158 describes the entries in a collection sort dictionary.

Table 158 - Entries in a collection sort dictionary

Key

Type

Value

Type

name

(Optional) The type of PDF object that this dictionary describes; if

present, shall be CollectionSort for a collection sort dictionary.

S

name or

(Required) The name or names of fields that the conforming reader

array

shall use to sort the items in the collection. If the value is a name, it

identifies a field described in the parent collection dictionary.

If the value is an array, each element of the array shall be a name that

identifies a field described in the parent collection dictionary. The

array form shall be used to allow additional fields to contribute to the

sort, where each additional field shall be used to break ties. More

specifically, if multiple collection item dictionaries have the same

value for the first field named in the array, the values for successive

fields named in the array shall be used for sorting, until a unique order

is determined or until the named fields are exhausted.

A

boolean

(Optional) If the value is a boolean, it specifies whether the

or array

conforming reader shall sort the items in the collection in ascending

order (true) or descending order (false). If the value is an array, each

element of the array shall be a boolean value that specifies whether

the entry at the same index in the S array shall be sorted in ascending

or descending order.

If the number of entries in the A array is larger than the number of

entries in the S array the extra entries in the A array shall be ignored.

If the number of entries in the A array is less than the number of

entries in the S array the missing entries in the A array shall be

assumed to be true.

Default value: true.

EXAMPLE 1

This example shows a collection dictionary representing an email in-box, where each item in the

collection is an email message. The actual email messages are contained in file specification dictionaries.

The organizational data associated with each email is described in a collection schema dictionary. Most

actual organizational data (from, to, date, and subject) is provided in a collection item dictionary, but the

size data comes from the embedded file parameter dictionary.

/Collection <<

/Type /Collection

/Schema <<

/Type /CollectionSchema

/from << /Subtype /S /N (From) /O 1 /V true /E false>>

/to << /Subtype /S /N (To) /O 2 /V true /E false >>

/date << /Subtype /D /N (Date received) /O 3 /V true /E false >>

/subject << /Subtype /S /N (Subject) /O 4 /V true /E false >>

/size << /Subtype /Size /N (Size) /O 5 /V true /E false >>

>>

/D (Doc1)

/View /D

/Sort << /S /date /A false >>

>>

373

Table 159 - Entries in a page label dictionary

Key

Type

Value

Type

name

(Optional) The type of PDF object that this dictionary describes; if present, shall be

PageLabel for a page label dictionary.

S

name

(Optional) The numbering style that shall be used for the numeric portion of each

page label:

D Decimal arabic numerals

R Uppercase roman numerals

r

Lowercase roman numerals

A Uppercase letters (A to Z for the first 26 pages, AA to ZZ for the next 26, and

so on)

a Lowercase letters (a to z for the first 26 pages, aa to zz for the next 26, and so

on)

There is no default numbering style; if no S entry is present, page labels shall

consist solely of a label prefix with no numeric portion.

NOTE

If the P entry (next) specifies the label prefix Contents, each page is

simply labeled Contents with no page number. (If the P entry is also missing or

empty, the page label is an empty string.)

P

text string

(Optional) The label prefix for page labels in this range.

St

integer

(Optional) The value of the numeric portion for the first page label in the range.

Subsequent pages shall be numbered sequentially from this value, which shall be

greater than or equal to 1. Default value: 1.

EXAMPLE

The following example shows a document with pages labeled

i, ii, iii, iv, 1, 2, 3, A-8, A-9, …

1 0 obj

<< /Type /Catalog

/PageLabels

<< /Nums [

0 <<

/S /r

>>

% A number tree containing

4 <<

/S /D >>

% three page label dictionaries

7 <<

/S /D

/P ( A- )

/St

8

>>

]

>>

…

>>

endobj

12.4.3

Articles

Some types of documents may contain sequences of content items that are logically connected but not

physically sequential.

EXAMPLE 1

A news story may begin on the first page of a newsletter and run over onto one or more nonconsecutive

interior pages.

To represent such sequences of physically discontiguous but logically related items, a PDF document may

define one or more articles (PDF 1.1). The sequential flow of an article shall be defined by an article thread; the

individual content items that make up the article are called beads on the thread. Conforming readers may

provide navigation facilities to allow the user to follow a thread from one bead to the next.

The optional Threads entry in the document catalogue (see 7.7.2, “Document Catalog”) holds an array of

thread dictionaries (Table 160) defining the document’s articles. Each individual bead within a thread shall be

375

represented by a bead dictionary (Table 161). The thread dictionary’s F entry shall refer to the first bead in the

thread; the beads shall be chained together sequentially in a doubly linked list through their N (next) and V

(previous) entries. In addition, for each page on which article beads appear, the page object (see 7.7.3, “Page

Tree”) shall contain a B entry whose value is an array of indirect references to the beads on the page, in

drawing order.

Table 160 - Entries in a thread dictionary

Key

Type

Value

Type

name

(Optional) The type of PDF object that this dictionary describes; if present,

shall be Thread for a thread dictionary.

F

dictionary

(Required; shall be an indirect reference) The first bead in the thread.

I

dictionary

(Optional) A thread information dictionary containing information about the

thread, such as its title, author, and creation date. The contents of this

dictionary shall conform to the syntax for the document information dictionary

(see 14.3.3, “Document Information Dictionary”).

Table 161 - Entries in a bead dictionary

Key

Type

Value

Type

name

(Optional) The type of PDF object that this dictionary describes; if present,

shall be Bead for a bead dictionary.

T

dictionary

(Required for the first bead of a thread; optional for all others; shall be an

indirect reference) The thread to which this bead belongs.

(PDF 1.1) This entry shall be permitted only for the first bead of a thread.

(PDF 1.2) It shall be permitted for any bead but required only for the first.

N

dictionary

(Required; shall be an indirect reference) The next bead in the thread. In the

last bead, this entry shall refer to the first bead.

V

dictionary

(Required; shall be an indirect reference) The previous bead in the thread. In

the first bead, this entry shall refer to the last bead.

P

dictionary

(Required; shall be an indirect reference) The page object representing the

page on which this bead appears.

R

rectangle

(Required) A rectangle specifying the location of this bead on the page.

EXAMPLE 2

The following example shows a thread with three beads.

22 0 obj

<<

/F 23 0 R

/I

<< /Title

(Man Bites Dog ) >>

>>

endobj

23 0 obj

<<

/T 22 0 R

/N 24 0 R

/V 25 0 R

/P 8 0 R

/R [ 158 247 318 905 ]

>>

endobj

24 0 obj

<<

/T 22 0 R

376

Table 162 - Entries in a transition dictionary

Key

Type

Value

Type

name

(Optional) The type of PDF object that this dictionary describes; if present, shall

be Trans for a transition dictionary.

S

name

(Optional) The transition style that shall be used when moving to this page from

another during a presentation. Default value: R.

Split

Two lines sweep across the screen, revealing the new page. The lines

may be either horizontal or vertical and may move inward from the

edges of the page or outward from the center, as specified by the Dm

and M entries, respectively.

Blinds

Multiple lines, evenly spaced across the screen, synchronously

sweep in the same direction to reveal the new page. The lines may be

either horizontal or vertical, as specified by the Dm entry. Horizontal

lines move downward; vertical lines move to the right.

Box

A rectangular box sweeps inward from the edges of the page or

outward from the center, as specified by the M entry, revealing the

new page.

Wipe

A single line sweeps across the screen from one edge to the other in

the direction specified by the Di entry, revealing the new page.

Dissolve

The old page dissolves gradually to reveal the new one.

Glitter

Similar to Dissolve, except that the effect sweeps across the page in a

wide band moving from one side of the screen to the other in the

direction specified by the Di entry.

R

The new page simply replaces the old one with no special transition

effect; the D entry shall be ignored.

Fly

(PDF 1.5) Changes are flown out or in (as specified by M), in the

direction specified by Di, to or from a location that is offscreen except

when Di is None.

Push

(PDF 1.5) The old page slides off the screen while the new page

slides in, pushing the old page out in the direction specified by Di.

Cover

(PDF 1.5) The new page slides on to the screen in the direction

specified by Di, covering the old page.

Uncover

(PDF 1.5) The old page slides off the screen in the direction

specified by Di, uncovering the new page in the direction

specified by Di.

Fade

(PDF 1.5) The new page gradually becomes visible through the

old one.

D

number

(Optional) The duration of the transition effect, in seconds. Default value: 1.

Dm

name

(Optional; Split and Blinds transition styles only) The dimension in which the

specified transition effect shall occur:

H Horizontal

V

Vertical

Default value: H.

M

name

(Optional; Split, Box and Fly transition styles only) The direction of motion for

the specified transition effect:

I

Inward from the edges of the page

O Outward from the center of the page

Default value: I.

378

Table 162 - Entries in a transition dictionary (continued)

Key

Type

Value

Di

number or

(Optional; Wipe, Glitter, Fly, Cover, Uncover and Push transition styles only)

name

The direction in which the specified transition effect shall moves, expressed in

degrees counterclockwise starting from a left-to-right direction. (This differs from

the page object’s Rotate entry, which is measured clockwise from the top.)

If the value is a number, it shall be one of:

0

Left to right

90

Bottom to top (Wipe only)

180

Right to left (Wipe only)

270

Top to bottom

315

Top-left to bottom-right (Glitter only)

If the value is a name, it shall be None, which is relevant only for the Fly

transition when the value of SS is not 1.0.

Default value: 0.

SS

number

(Optional; PDF 1.5; Fly transition style only) The starting or ending scale at

which the changes shall be drawn. If M specifies an inward transition, the scale

of the changes drawn shall progress from SS to 1.0 over the course of the

transition. If M specifies an outward transition, the scale of the changes drawn

shall progress from 1.0 to SS over the course of the transition

Default: 1.0.

B

boolean

(Optional; PDF 1.5; Fly transition style only) If true, the area that shall be flown

in is rectangular and opaque. Default: false.

NOTE 3

Figure 56 illustrates the relationship between transition duration (D in the transition dictionary) and display

duration (Dur in the page object). Note that the transition duration specified for a page (page 2 in the figure)

governs the transition to that page from another page; the transition from the page is governed by the next

page’s transition duration.

Transition from

Transition from

page 1 to page 2

Page 2 displayed

page 2 to page 3

Transition duration

Display duration for page 2

Transition duration

for page 2

for page 3

Figure 56 - Presentation timing

EXAMPLE

The following example shows the presentation parameters for a page to be displayed for 5 seconds.

Before the page is displayed, there is a 3.5-second transition in which two vertical lines sweep outward

from the center to the edges of the page.

10 0 obj

<<

/Type /Page

/Parent 4 0 R

/Contents 16 0 R

/Dur 5

/Trans

<<

/Type /Trans

/D 3.5

/S /Split

/Dm /V

/M /O

>>

>>

endobj

379

12.4.4.2

Sub-page Navigation

Sub-page navigation (PDF 1.5) provides the ability to navigate not only between pages but also between

different states of the same page.

NOTE 1

A single page in a PDF presentation could have a series of bullet points that could be individually turned on

and off. In such an example, the bullets would be represented by optional content (see 8.11.2, “Optional

Content Groups”), and each state of the page would be represented as a navigation node.

NOTE 2

Conforming readers should save the state of optional content groups when a user enters presentation mode

and restore it when presentation mode ends. This ensures, for example, that transient changes to bullets do

not affect the printing of the document.

A navigation node dictionary (see Table 163) specifies actions to execute when the user makes a navigation

request.

EXAMPLE

Pressing an arrow key.

The navigation nodes on a page form a doubly linked list by means of their Next and Prev entries. The primary

node on a page shall be determined by the optional PresSteps entry in a page dictionary (see Table 30).

NOTE 3

A conforming reader should respect navigation nodes only when in presentation mode

(see

12.4.4,

“Presentations”).

Table 163 - Entries in a navigation node dictionary

Key

Type

Value

Type

name

(Optional) The type of PDF object that this dictionary describes; shall be

NavNode for a navigation node dictionary.

NA

dictionary

(Optional) An action (which may be the first in a sequence of actions) that

shall be executed when a user navigates forward.

PA

dictionary

(Optional) An action (which may be the first in a sequence of actions) that

shall be executed when a user navigates backward.

Next

dictionary

(Optional) The next navigation node, if any.

Prev

dictionary

(Optional) The previous navigation node, if any.

Dur

number

(Optional) The maximum number of seconds before the conforming reader

shall automatically advance forward to the next navigation node. If this entry

is not specified, no automatic advance shall occur.

A conforming reader shall maintain a current navigation node. When a user navigates to a page, if the page

dictionary has a PresSteps entry, the node specified by that entry shall become the current node. (Otherwise,

there is no current node.) If the user requests to navigate forward (such as an arrow key press) and there is a

current navigation node, the following shall occur:

a) The sequence of actions specified by NA (if present) shall be executed.

If NA specifies an action that navigates to another page, the following actions for navigating to another

page take place, and Next should not be present.

b) The node specified by Next (if present) shall become the new current navigation node.

Similarly, if the user requests to navigate backward and there is a current navigation node, the following shall

occur:

a) The sequence of actions specified by PA (if present) shall be executed.

380

WE HAVE BEEN TRACKING GREAT EMPLOYEES SINCE 1981,

when we began research on our book Te 100 Best

Companies to

of

Comment

more than 1,0

ost

viable candida

This is the text associated with the

to

highlight annotation.

participate. (T

en

years old and

We asked

25

randomly sele

rk

Trust Index.

he

Great Place to

ate

trust in ma

nd

camaraderie.

Each com

itt

People Practi

ge

questionnaire

ct,

Hewitt Asso

ng

management c

ur

candidates to send us additional corporate materials, such

Figure 57 - Open annotation

Conforming readers may permit the user to navigate through the annotations on a page by using the keyboard

(in particular, the tab key). Beginning with PDF 1.5, PDF producers may make the navigation order explicit with

the optional Tabs entry in a page object (see Table 30). The following are the possible values for this entry:

•

R (row order): Annotations shall be visited in rows running horizontally across the page. The direction

within a row shall be determined by the Direction entry in the viewer preferences dictionary (see 12.2,

“Viewer Preferences”). The first annotation that shall be visited is the first annotation in the topmost row.

When the end of a row is encountered, the first annotation in the next row shall be visited.

•

C (column order): Annotations shall be visited in columns running vertically up and down the page.

Columns shall be ordered by the Direction entry in the viewer preferences dictionary (see 12.2, “Viewer

Preferences”). The first annotation that shall be visited is the one at the top of the first column. When the

end of a column is encountered, the first annotation in the next column shall be visited.

•

S (structure order): Annotations shall be visited in the order in which they appear in the structure tree (see

14.7, “Logical Structure”). The order for annotations that are not included in the structure tree shall be

determined in a manner of the conforming reader's choosing.

These descriptions assume the page is being viewed in the orientation specified by the Rotate entry.

Conceptually, the behaviour of each annotation type may be implemented by a software module called an

annotation handler. A conforming reader shall provide annotation handlers for all of the conforming annotation

types. The set of annotation types is extensible. A conforming reader shall provide certain expected behaviour

for all annotation types that it does not recognize, as documented in 12.5.2, “Annotation Dictionaries.”

12.5.2

Annotation Dictionaries

The optional Annots entry in a page object (see 7.7.3, “Page Tree”) holds an array of annotation dictionaries,

each representing an annotation associated with the given page. Table 164 shows the required and optional

entries that are common to all annotation dictionaries. The dictionary may contain additional entries specific to

a particular annotation type; see the descriptions of individual annotation types in 12.5.6, “Annotation Types,”

for details. A given annotation dictionary shall be referenced from the Annots array of only one page. This

requirement applies only to the annotation dictionary itself, not to subsidiary objects, which may be shared

among multiple annotations.

382

Table 164 - Entries common to all annotation dictionaries

Key

Type

Value

Type

name

(Optional) The type of PDF object that this dictionary describes; if

present, shall be Annot for an annotation dictionary.

Subtype

name

(Required) The type of annotation that this dictionary describes; see

Table 169 for specific values.

Rect

rectangle

(Required) The annotation rectangle, defining the location of the

annotation on the page in default user space units.

Contents

text string

(Optional) Text that shall be displayed for the annotation or, if this type of

annotation does not display text, an alternate description of the

annotation’s contents in human-readable form. In either case, this text is

useful when extracting the document’s contents in support of

accessibility to users with disabilities or for other purposes (see 14.9.3,

“Alternate Descriptions”). See

12.5.6,

“Annotation Types” for more

details on the meaning of this entry for each annotation type.

P

dictionary

(Optional except as noted below; PDF 1.3; not used in FDF files) An

indirect reference to the page object with which this annotation is

associated.

This entry shall be present in screen annotations associated with

rendition actions (PDF 1.5; see 12.5.6.18, “Screen Annotations” and

12.6.4.13, “Rendition Actions”).

NM

text string

(Optional; PDF 1.4) The annotation name, a text string uniquely

identifying it among all the annotations on its page.

M

date or

(Optional; PDF 1.1) The date and time when the annotation was most

text string

recently modified. The format should be a date string as described in

7.9.4, “Dates,” but conforming readers shall accept and display a string

in any format.

F

integer

(Optional; PDF 1.1) A set of flags specifying various characteristics of

the annotation (see 12.5.3, “Annotation Flags”). Default value: 0.

AP

dictionary

(Optional; PDF 1.2) An appearance dictionary specifying how the

annotation shall be presented visually on the page

(see

12.5.5,

“Appearance Streams”). Individual annotation handlers may ignore this

entry and provide their own appearances.

AS

name

(Required if the appearance dictionary AP contains one or more

subdictionaries; PDF 1.2) The annotation’s appearance state, which

selects the applicable appearance stream from an appearance

subdictionary (see Section 12.5.5, “Appearance Streams”).

383

Table 164 - Entries common to all annotation dictionaries (continued)

Key

Type

Value

Border

array

(Optional) An array specifying the characteristics of the annotation’s

border, which shall be drawn as a rounded rectangle.

(PDF 1.0) The array consists of three numbers defining the horizontal

corner radius, vertical corner radius, and border width, all in default user

space units. If the corner radii are 0, the border has square (not rounded)

corners; if the border width is 0, no border is drawn.

(PDF 1.1) The array may have a fourth element, an optional dash array

defining a pattern of dashes and gaps that shall be used in drawing the

border. The dash array shall be specified in the same format as in the

line dash pattern parameter of the graphics state (see 8.4.3.6, “Line

Dash Pattern”).

EXAMPLE

A Border value of [ 0 0 1 [ 3 2 ] ] specifies a border 1

unit wide, with square corners, drawn with

3-unit

dashes alternating with 2-unit gaps.

NOTE

(PDF 1.2) The dictionaries for some annotation types (such

as free text and polygon annotations) can include the BS

entry. That entry specifies a border style dictionary that has

more settings than the array specified for the Border entry.

If an annotation dictionary includes the BS entry, then the

Border entry is ignored.

Default value: [ 0

0 1 ].

C

array

(Optional; PDF 1.1) An array of numbers in the range

0.0 to

1.0,

representing a colour used for the following purposes:

The background of the annotation’s icon when closed

The title bar of the annotation’s pop-up window

The border of a link annotation

The number of array elements determines the colour space in which the

colour shall be defined:

0

No colour; transparent

1

DeviceGray

3

DeviceRGB

4

DeviceCMYK

StructParent

integer

(Required if the annotation is a structural content item; PDF 1.3) The

integer key of the annotation’s entry in the structural parent tree (see

14.7.4.4, “Finding Structure Elements from Content Items”).

OC

dictionary

(Optional; PDF 1.5) An optional content group or optional content

membership dictionary (see 8.11, “Optional Content”) specifying the

optional content properties for the annotation. Before the annotation is

drawn, its visibility shall be determined based on this entry as well as the

annotation flags specified in the F entry (see 12.5.3, “Annotation Flags”).

If it is determined to be invisible, the annotation shall be skipped, as if it

were not in the document.

12.5.3

Annotation Flags

The value of the annotation dictionary’s F entry is an integer interpreted as one-bit flags specifying various

characteristics of the annotation. Bit positions within the flag word shall be numbered from low-order to high-

order, with the lowest-order bit numbered 1. Table 165 shows the meanings of the flags; all other bits of the

integer shall be set to 0.

384

Table 165 - Annotation flags

Bit

Name

Meaning

position

1

Invisible

If set, do not display the annotation if it does not belong to one of the

standard annotation types and no annotation handler is available. If

clear, display such an unknown annotation using an appearance

stream specified by its appearance dictionary, if any

(see 12.5.5,

“Appearance Streams”).

2

Hidden

(PDF 1.2) If set, do not display or print the annotation or allow it to

interact with the user, regardless of its annotation type or whether an

annotation handler is available.

NOTE 1

In cases where screen space is limited, the ability to hide

and show annotations selectively can be used in

combination with appearance streams

(see

12.5.5,

“Appearance Streams”) to display auxiliary

pop-up

information similar in function to online help systems.

3

Print

(PDF 1.2) If set, print the annotation when the page is printed. If clear,

never print the annotation, regardless of whether it is displayed on the

screen.

NOTE 2

This can be useful for annotations representing interactive

pushbuttons, which would serve no meaningful purpose

on the printed page.

4

NoZoom

(PDF 1.3) If set, do not scale the annotation’s appearance to match the

magnification of the page. The location of the annotation on the page

(defined by the upper-left corner of its annotation rectangle) shall

remain fixed, regardless of the page magnification. See further

discussion following this Table.

5

NoRotate

(PDF 1.3) If set, do not rotate the annotation’s appearance to match

the rotation of the page. The upper-left corner of the annotation

rectangle shall remain in a fixed location on the page, regardless of the

page rotation. See further discussion following this Table.

6

NoView

(PDF 1.3) If set, do not display the annotation on the screen or allow it

to interact with the user. The annotation may be printed (depending on

the setting of the Print flag) but should be considered hidden for

purposes of on-screen display and user interaction.

7

ReadOnly

(PDF 1.3) If set, do not allow the annotation to interact with the user.

The annotation may be displayed or printed (depending on the settings

of the NoView and Print flags) but should not respond to mouse clicks

or change its appearance in response to mouse motions.

This flag shall be ignored for widget annotations; its function is

subsumed by the ReadOnly flag of the associated form field (see

Table 221).

8

Locked

(PDF 1.4) If set, do not allow the annotation to be deleted or its

properties (including position and size) to be modified by the user.

However, this flag does not restrict changes to the annotation’s

contents, such as the value of a form field.

9

ToggleNoView

(PDF 1.5) If set, invert the interpretation of the NoView flag for certain

events.

NOTE 3

A typical use is to have an annotation that appears only

when a mouse cursor is held over it.

10

LockedContents

(PDF 1.7) If set, do not allow the contents of the annotation to be

modified by the user. This flag does not restrict deletion of the

annotation or changes to other annotation properties, such as position

and size.

385

If the NoZoom flag is set, the annotation shall always maintain the same fixed size on the screen and shall be

unaffected by the magnification level at which the page itself is displayed. Similarly, if the NoRotate flag is set,

the annotation shall retain its original orientation on the screen when the page is rotated (by changing the

Rotate entry in the page object; see 7.7.3, “Page Tree”).

In either case, the annotation’s position shall be determined by the coordinates of the upper-left corner of its

annotation rectangle, as defined by the Rect entry in the annotation dictionary and interpreted in the default

user space of the page. When the default user space is scaled or rotated, the positions of the other three

corners of the annotation rectangle are different in the altered user space than they were in the original user

space. The conforming reader shall perform this alteration automatically. However, it shall not actually change

the annotation’s Rect entry, which continues to describe the annotation’s relationship with the unscaled,

unrotated user space.

NOTE

Figure 58 shows how an annotation whose NoRotate flag is set remains upright when the page it is on is

rotated 90 degrees clockwise. The upper-left corner of the annotation remains at the same point in default user

space; the annotation pivots around that point.

(0, 0)

abcdefghijklm

nopqrstuvwxyz

(0, 0)

Before page rotation

After page rotation

Figure 58 - Coordinate adjustment with the NoRotate flag

12.5.4

Border Styles

An annotation may optionally be surrounded by a border when displayed or printed. If present, the border shall

be drawn completely inside the annotation rectangle. In PDF 1.1, the characteristics of the border shall be

specified by the Border entry in the annotation dictionary (see Table 164). Beginning with PDF 1.2, the border

characteristics for some types of annotations may instead be specified in a border style dictionary designated

by the annotation’s BS entry. Such dictionaries may also be used to specify the width and dash pattern for the

lines drawn by line, square, circle, and ink annotations. Table 166 summarizes the contents of the border style

dictionary. If neither the Border nor the BS entry is present, the border shall be drawn as a solid line with a

width of 1 point.

Table 166 - Entries in a border style dictionary

Key

Type

Value

Type

name

(Optional) The type of PDF object that this dictionary describes; if present,

shall be Border for a border style dictionary.

W

number

(Optional) The border width in points. If this value is 0, no border shall drawn.

Default value: 1.

386

Table 166 - Entries in a border style dictionary (continued)

Key

Type

Value

S

name

(Optional) The border style:

S

(Solid) A solid rectangle surrounding the annotation.

D

(Dashed) A dashed rectangle surrounding the annotation. The dash

pattern may be specified by the D entry.

B

(Beveled) A simulated embossed rectangle that appears to be raised

above the surface of the page.

I

(Inset) A simulated engraved rectangle that appears to be recessed

below the surface of the page.

U

(Underline) A single line along the bottom of the annotation rectangle.

A conforming reader shall tolerate other border styles that it does not

recognize and shall use the default value.

D

array

(Optional) A dash array defining a pattern of dashes and gaps that shall be

used in drawing a dashed border (border style D in the S entry). The dash

array shall be specified in the same format as in the line dash pattern

parameter of the graphics state (see 8.4.3.6, “Line Dash Pattern”). The dash

phase is not specified and shall be assumed to be 0.

EXAMPLE

A D entry of [ 3 2 ] specifies a border drawn with 3-point

dashes alternating with 2-point gaps.

Default value: [ 3 ].

Beginning with PDF 1.5, some annotations (square, circle, and polygon) may have a BE entry, which is a

border effect dictionary that specifies an effect that shall be applied to the border of the annotations. Beginning

with PDF 1.6, the free text annotation may also have a BE entry. Table 167 describes the entries in a border

effect dictionary.

Table 167 - Entries in a border effect dictionary

Key

Type

Value

S

name

(Optional) A name representing the border effect to apply. Possible values

are:

S No effect: the border shall be as described by the annotation dictionary’s

BS entry.

C The border should appear “cloudy”. The width and dash array specified by

BS shall be honored.

Default value: S.

I

number

(Optional; valid only if the value of S is C) A number describing the intensity of

the effect, in the range 0 to 2. Default value: 0.

12.5.5

Appearance Streams

Beginning with PDF 1.2, an annotation may specify one or more appearance streams as an alternative to the

simple border and colour characteristics available in earlier versions. Appearance streams enable the

annotation to be presented visually in different ways to reflect its interactions with the user. Each appearance

stream is a form XObject (see 8.10, “Form XObjects”): a self-contained content stream that shall be rendered

inside the annotation rectangle.

The algorithm outlined in this sub-clause shall be used to map from the coordinate system of the appearance

XObject (as defined by its Matrix entry; see Table 97) to the annotation’s rectangle in default user space:

387

Table 168 - Entries in an appearance dictionary

Key

Type

Value

N

stream or dictionary

(Required) The annotation’s normal appearance.

R

stream or dictionary

(Optional) The annotation’s rollover appearance. Default value: the

value of the N entry.

D

stream or dictionary

(Optional) The annotation’s down appearance. Default value: the value

of the N entry.

Each entry in the appearance dictionary may contain either a single appearance stream or an appearance

subdictionary. In the latter case, the subdictionary shall define multiple appearance streams corresponding to

different appearance states of the annotation.

EXAMPLE

An annotation representing an interactive check box may have two appearance states named On and Off.

Its appearance dictionary may be defined as

/AP <<

/N <<

/On formXObject₁

/Off formXObject₂

>>

/D

<<

/On formXObject₃

/Off formXObject₄

>>

>>

where formXObject₁ and formXObject₂ define the check box’s normal appearance in its checked and

unchecked states, and formXObject₃ and formXObject₄ provide visual feedback, such as emboldening its

outline, when the user clicks it. (No R entry is defined because no special appearance is needed when the

user moves the cursor over the check box without pressing the mouse button.) The choice between the

checked and unchecked appearance states is determined by the AS entry in the annotation dictionary

(see Table 164).

NOTE 3

If a conforming reader does not have native support for a particular annotation type conforming readers shall

display the annotation with its normal (N) appearance. Conforming readers shall also attempt to provide

reasonable behavior (such as displaying nothing) if an annotation’s AS entry designates an appearance state

for which no appearance is defined in the appearance dictionary.

For convenience in managing appearance streams that are used repeatedly, the AP entry in a PDF document’s

name dictionary (see 7.7.4, “Name Dictionary”) may contain a name tree mapping name strings to appearance

streams. The name strings have no standard meanings; no PDF objects may refer to appearance streams by

name.

12.5.6

Annotation Types

12.5.6.1

General

PDF supports the standard annotation types listed in Table 169. The following sub-clauses describe each of

these types in detail.

The values in the first column of Table 169 represent the value of the annotation dictionary’s Subtype entry.

The third column indicates whether the annotation is a markup annotation, as described in 12.5.6.2, “Markup

Annotations.” The sub-clause also provides more information about the value of the Contents entry for

different annotation types.

389

Table 169 - Annotation types

Annotation type

Description

Markup

Discussed in sub-clause

Text

Text annotation

Yes

12.5.6.4, “Text Annotations”

Link

Link annotation

No

12.5.6.5, “Link Annotations”

FreeText

(PDF 1.3) Free text annotation

Yes

12.5.6.6, “Free Text Annotations”

Line

(PDF 1.3) Line annotation

Yes

12.5.6.7, “Line Annotations”

Square

(PDF 1.3) Square annotation

Yes

12.5.6.8, “Square and Circle

Annotations”

Circle

(PDF 1.3) Circle annotation

Yes

12.5.6.8, “Square and Circle

Annotations”

Polygon

(PDF 1.5) Polygon annotation

Yes

12.5.6.9, “Polygon and Polyline

Annotations”

PolyLine

(PDF 1.5) Polyline annotation

Yes

12.5.6.9, “Polygon and Polyline

Annotations”

Highlight

(PDF 1.3) Highlight annotation

Yes

12.5.6.10, “Text Markup Annotations”

Underline

(PDF 1.3) Underline

Yes

12.5.6.10, “Text Markup Annotations”

annotation

Squiggly

(PDF 1.4) Squiggly-underline

Yes

12.5.6.10, “Text Markup Annotations”

annotation

StrikeOut

(PDF 1.3) Strikeout annotation

Yes

12.5.6.10, “Text Markup Annotations”

Stamp

(PDF 1.3) Rubber stamp

Yes

12.5.6.12, “Rubber Stamp Annotations”

annotation

Caret

(PDF 1.5) Caret annotation

Yes

12.5.6.11, “Caret Annotations”

Ink

(PDF 1.3) Ink annotation

Yes

12.5.6.13, “Ink Annotations”

Popup

(PDF 1.3) Pop-up annotation

No

12.5.6.14, “Pop-up Annotations”

FileAttachment

(PDF 1.3) File attachment

Yes

12.5.6.15, “File Attachment Annotations”

annotation

Sound

(PDF 1.2) Sound annotation

Yes

12.5.6.16, “Sound Annotations”

Movie

(PDF 1.2) Movie annotation

No

12.5.6.17, “Movie Annotations”

Widget

(PDF 1.2) Widget annotation

No

12.5.6.19, “Widget Annotations”

Screen

(PDF 1.5) Screen annotation

No

12.5.6.18, “Screen Annotations”

PrinterMark

(PDF 1.4) Printer’s mark

No

12.5.6.20, “Printer’s Mark Annotations”

annotation

TrapNet

(PDF 1.3) Trap network

No

12.5.6.21, “Trap Network Annotations”

annotation

Watermark

(PDF 1.6) Watermark

No

12.5.6.22, “Watermark Annotations”

annotation

3D

(PDF 1.6) 3D annotation

No

13.6.2, “3D Annotations”

Redact

(PDF 1.7) Redact annotation

Yes

12.5.6.23, “Redaction Annotations”

390

12.5.6.2

Markup Annotations

As mentioned in 12.5.2, “Annotation Dictionaries,” the meaning of an annotation’s Contents entry varies by

annotation type. Typically, it is the text that shall be displayed for the annotation or, if the annotation does not

display text, an alternate description of the annotation’s contents in human-readable form. In either case, the

Contents entry is useful when extracting the document’s contents in support of accessibility to users with

disabilities or for other purposes (see 14.9.3, “Alternate Descriptions”).

Many annotation types are defined as markup annotations because they are used primarily to mark up PDF

documents (see Table 170). These annotations have text that appears as part of the annotation and may be

displayed in other ways by a conforming reader, such as in a Comments pane.

Markup annotations may be divided into the following groups:

•

Free text annotations display text directly on the page. The annotation’s Contents entry specifies the

displayed text.

•

Most other markup annotations have an associated pop-up window that may contain text. The annotation’s

Contents entry specifies the text that shall be displayed when the pop-up window is opened. These

include text, line, square, circle, polygon, polyline, highlight, underline, squiggly-underline, strikeout, rubber

stamp, caret, ink, and file attachment annotations.

•

Sound annotations do not have a pop-up window but may also have associated text specified by the

Contents entry.

When separating text into paragraphs, a CARRIAGE RETURN (0Dh) shall be used and not, for example, a

LINE FEED character (0Ah).

NOTE 1

A subset of markup annotations is called text markup annotations (see 12.5.6.10, “Text Markup Annotations”).

The remaining annotation types are not considered markup annotations:

•

The pop-up annotation type shall not appear by itself; it shall be associated with a markup annotation that uses it to

display text.

NOTE 2

If an annotation has no parent, the Contents entry shall represent the text of the annotation, otherwise it shall

be ignored by a conforming reader.

•

For all other annotation types (Link, Movie, Widget, PrinterMark, and TrapNet), the Contents entry shall

provide an alternate representation of the annotation’s contents in human-readable form, which is useful

when extracting the document’s contents in support of accessibility to users with disabilities or for other

purposes (see 14.9.3, “Alternate Descriptions”).

Table 170 lists entries that apply to all markup annotations.

Table 170 - Additional entries specific to markup annotations

Key

Type

Value

T

text string

(Optional; PDF 1.1) The text label that shall be displayed in the title bar of

the annotation’s pop-up window when open and active. This entry shall

identify the user who added the annotation.

Popup

dictionary

(Optional; PDF 1.3) An indirect reference to a pop-up annotation for

entering or editing the text associated with this annotation.

391

Table 170 - Additional entries specific to markup annotations (continued)

Key

Type

Value

CA

number

(Optional; PDF 1.4) The constant opacity value that shall be used in

painting the annotation (see Sections 11.2, “Overview of Transparency,”

and 11.3.7, “Shape and Opacity Computations”). This value shall apply to

all visible elements of the annotation in its closed state (including its

background and border) but not to the pop-up window that appears when

the annotation is opened.

The specified value shall not used if the annotation has an appearance

stream (see 12.5.5, “Appearance Streams”); in that case, the appearance

stream shall specify any transparency. (However, if the compliant viewer

regenerates the annotation’s appearance stream, it may incorporate the

CA value into the stream’s content.)

The implicit blend mode (see 11.3.5, “Blend Mode””) is Normal. Default

value: 1.0.

If no explicit appearance stream is defined for the annotation, it may be

painted by implementation-dependent means that do not necessarily

conform to the PDF imaging model; in this case, the effect of this entry is

implementation-dependent as well.

RC

text string

(Optional; PDF 1.5) A rich text string (see 12.7.3.4, “Rich Text Strings”)

or text

that shall be displayed in the pop-up window when the annotation is

stream

opened.

CreationDate

date

(Optional; PDF

1.5) The date and time

(7.9.4,

“Dates”) when the

annotation was created.

IRT

dictionary

(Required if an RT entry is present, otherwise optional; PDF 1.5) A

reference to the annotation that this annotation is “in reply to.” Both

annotations shall be on the same page of the document. The relationship

between the two annotations shall be specified by the RT entry.

If this entry is present in an FDF file (see 12.7.7, “Forms Data Format”), its

type shall not be a dictionary but a text string containing the contents of

the NM entry of the annotation being replied to, to allow for a situation

where the annotation being replied to is not in the same FDF file.

Subj

text string

(Optional; PDF 1.5) Text representing a short description of the subject

being addressed by the annotation.

RT

name

(Optional; meaningful only if IRT is present; PDF 1.6) A name specifying

the relationship

(the

“reply type”) between this annotation and one

specified by IRT. Valid values are:

R

The annotation shall be considered a reply to the annotation

specified by IRT. Conforming readers shall not display replies

to an annotation individually but together in the form of

threaded comments.

Group The annotation shall be grouped with the annotation specified

by IRT; see the discussion following this Table.

Default value: R.

IT

name

(Optional; PDF

1.6) A name describing the intent of the markup

annotation. Intents allow conforming readers to distinguish between

different uses and behaviors of a single markup annotation type. If this

entry is not present or its value is the same as the annotation type, the

annotation shall have no explicit intent and should behave in a generic

manner in a conforming reader.

Free text annotations (Table 174), line annotations (Table 175), polygon

annotations (Table 178), and (PDF 1.7) polyline annotations (Table 178)

have defined intents, whose values are enumerated in the corresponding

tables.

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