Table 28 – Entries in the catalog dictionary

Key

Type

Value

Type

name

(Required) The type of PDF object that this dictionary describes; shall be Catalog for the catalog dictionary.

Version

name

(Optional; PDF 1.4) The version of the PDF specification to which the document conforms (for example, 1.4) if later than the version specified in the file’s header (see 7.5.2, "File Header" ). If the header specifies a later version, or if this entry is absent, the document shall conform to the version specified in the header. This entry enables a conforming writer to update the version using an incremental update; see 7.5.6, "Incremental Updates."

The value of this entry shall be a name object, not a number, and therefore shall be preceded by a SOLIDUS (2Fh) character (/) when written in the PDF file (for example, /1.4).

Extensions

dictionary

(Optional; ISO 32000) An extensions dictionary containing developer prefix identification and version numbers for developer extensions that occur in this document. 7.12, “Extensions Dictionary” , describes this dictionary and how it shall be used.

Pages

dictionary

(Required; shall be an indirect reference) The page tree node that shall be the root of the document’s page tree (see 7.7.3, "Page Tree" ).

PageLabels

number tree

(Optional; PDF 1.3) A number tree (see 7.9.7, "Number Trees" ) defining the page labelling for the document. The keys in this tree shall be page indices; the corresponding values shall be page label dictionaries (see 12.4.2, "Page Labels" ). Each page index shall denote the first page in a labelling range to which the specified page label dictionary applies. The tree shall include a value for page index 0.

Names

dictionary

(Optional; PDF 1.2) The document’s name dictionary (see 7.7.4, "Name Dictionary" ).

Dests

dictionary

(Optional; PDF 1.1; shall be an indirect reference) A dictionary of names and corresponding destinations (see 12.3.2.3, "Named Destinations" ).

ViewerPreferences

dictionary

(Optional; PDF 1.2) A viewer preferences dictionary (see 12.2, "Viewer Preferences" ) specifying the way the document shall be displayed on the screen. If this entry is absent, conforming readers shall use their own current user preference settings.

PageLayout

name

(Optional) A name object specifying the page layout shall be used when the document is opened:

SinglePageDisplay one page at a time

OneColumnDisplay the pages in one column

TwoColumnLeftDisplay the pages in two columns, with odd-numbered pages on the left

TwoColumnRightDisplay the pages in two columns, with odd-numbered pages on the right

TwoPageLeft(PDF 1.5) Display the pages two at a time, with odd-numbered pages on the left

TwoPageRight(PDF 1.5) Display the pages two at a time, with odd-numbered pages on the right

Default value: SinglePage.

PageMode

name

(Optional) A name object specifying how the document shall be displayed when opened:

UseNoneNeither document outline nor thumbnail images visible

UseOutlinesDocument outline visible

UseThumbsThumbnail images visible

FullScreenFull-screen mode, with no menu bar, window controls, or any other window visible

UseOC(PDF 1.5) Optional content group panel visible

UseAttachments(PDF 1.6) Attachments panel visible

Default value: UseNone.

Outlines

dictionary

(Optional; shall be an indirect reference) The outline dictionary that shall be the root of the document’s outline hierarchy (see 12.3.3, "Document Outline" ).

Threads

array

(Optional; PDF 1.1; shall be an indirect reference) An array of thread dictionaries that shall represent the document’s article threads (see 12.4.3, "Articles" ).

OpenAction

array or dictionary

(Optional; PDF 1.1) A value specifying a destination that shall be displayed or an action that shall be performed when the document is opened. The value shall be either an array defining a destination (see 12.3.2, "Destinations" ) or an action dictionary representing an action ( 12.6, "Actions" ). If this entry is absent, the document shall be opened to the top of the first page at the default magnification factor.

AA

dictionary

(Optional; PDF 1.4) An additional-actions dictionary defining the actions that shall be taken in response to various trigger eventsaffecting the document as a whole (see 12.6.3, "Trigger Events" ).

URI

dictionary

(Optional; PDF 1.1) A URI dictionary containing document-level information for URI (uniform resource identifier) actions (see 12.6.4.7, "URI Actions" ).

AcroForm

dictionary

(Optional; PDF 1.2) The document’s interactive form (AcroForm) dictionary (see 12.7.2, "Interactive Form Dictionary" ).

Metadata

stream

(Optional; PDF 1.4; shall be an indirect reference) A metadata stream that shall contain metadata for the document (see 14.3.2, "Metadata Streams" ).

StructTreeRoot

dictionary

(Optional; PDF 1.3) The document’s structure tree root dictionary (see 14.7.2, "Structure Hierarchy" ).

MarkInfo

dictionary

(Optional; PDF 1.4) A mark information dictionary that shall contain information about the document’s usage of Tagged PDF conventions (see 14.7, "Logical Structure" ).

Lang

text string

(Optional; PDF 1.4) A language identifier that shall specify the natural language for all text in the document except where overridden by language specifications for structure elements or marked content (see 14.9.2, "Natural Language Specification" ). If this entry is absent, the language shall be considered unknown.

SpiderInfo

dictionary

(Optional; PDF 1.3) A Web Capture information dictionary that shall contain state information used by any Web Capture extension (see 14.10.2, "Web Capture Information Dictionary" ).

OutputIntents

array

(Optional; PDF 1.4) An array of output intent dictionaries that shall specify the colour characteristics of output devices on which the document might be rendered (see 14.11.5, "Output Intents" ).

PieceInfo

dictionary

(Optional; PDF 1.4) A page-piece dictionary associated with the document (see 14.5, "Page-Piece Dictionaries" ).

OCProperties

dictionary

(Optional; PDF 1.5; required if a document contains optional content) The document’s optional content properties dictionary (see 8.11.4, "Configuring Optional Content" ).

Perms

dictionary

(Optional; PDF 1.5) A permissions dictionary that shall specify user access permissions for the document. 12.8.4, "Permissions" , describes this dictionary and how it shall be used.

Legal

dictionary

(Optional; PDF 1.5) A dictionary that shall contain attestations regarding the content of a PDF document, as it relates to the legality of digital signatures (see 12.8.5, "Legal Content Attestations" ).

Requirements

array

(Optional; PDF 1.7) An array of requirement dictionaries that shall represent requirements for the document. 12.10, "Document Requirements" , describes this dictionary and how it shall be used.

Collection

dictionary

(Optional; PDF 1.7) A collection dictionary that a conforming reader shall use to enhance the presentation of file attachments stored in the PDF document. (see 12.3.5, "Collections" ).

NeedsRendering

boolean

(Optional; PDF 1.7) A flag used to expedite the display of PDF documents containing XFA forms. It specifies whether the document shall be regenerated when the document is first opened.

See the XML Forms Architecture (XFA) Specification( Bibliography ).

Default value: false.