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Standard PDF tags
This
section describes the standard tag types that apply to tagged PDFs.
These standard tags provide assistive software and devices with
semantic and structural elements to use to interpret document structure
and present content in a useful manner.
The PDF tags architecture
is extensible, so any PDF document can contain any tag set that
an authoring application decides to use. For example, a PDF can
have XML tags that came in from an XML schema. Custom tags that
you define (such as tag names generated from paragraph styles of
an authoring application) need a role map. The role map matches
each custom tag to a standard tag here. When assistive software
encounters a custom tag, the software can check this role map and
properly interpret the tags. Tagging PDFs by using one of the methods described
here generally produces a correct role map for the document.
Note: You
can view and edit the role map of a PDF by choosing Options >
Edit Role Map in the Tags tab.
The standard Adobe element
tag types are available in the New Tag dialog box. They are also
available in the TouchUp Properties dialog box in Acrobat Pro or Acrobat
Pro Extended. Adobe strongly encourages using these tag types because
they provide the best results when tagged content is converted to
a different format. These formats include HTML, Microsoft Word,
or an accessible text format for use by other assistive technologies.
Block-level
elements are page elements that consist of text laid out in paragraph-like
forms. Block-level elements are part of a document’s logical structure.
Such elements are further classified as container elements, heading
and paragraph elements, label and list elements, special text elements,
and table elements.
Container elementsContainer elements are the highest level of
element and provide hierarchical grouping for other block-level
elements.
- Document
- Document element. The root element of a document’s tag tree.
- Part
- Part element. A large division of a document; may group smaller
units of content together, such as division elements, article elements,
or section elements.
- Div
- Division element. A generic block-level element or group
of block-level elements.
- Art
- Article element. A self-contained body of text considered
to be a single narrative.
- Sect
- Section element. A general container element type, comparable
to Division (DIV Class="Sect") in HTML, which is
usually a component of a part element or an article element.
Heading and paragraph elementsHeading and paragraph elements are paragraph-like,
block-level elements that include specific level heading and generic
paragraph (P) tags. A heading (H) element
should appear as the first child of any higher-level division. Six
levels of headings (H1 to H6)
are available for applications that don’t hierarchically nest sections.
Label and list elementsLabel and list elements are block-level elements
used for structuring lists.
- L
- List element. Any sequence of items of similar meaning or
other relevance; immediate child elements should be list item elements.
- LI
- List item element. Any one member of a list; may have a label
element (optional) and a list body element (required) as a child.
- LBL
- Label element. A bullet, name, or number that identifies
and distinguishes an element from others in the same list.
- LBody
- List item body element. The descriptive content of a list
item.
Special text elementsSpecial text elements identify text that isn’t
used as a generic paragraph (P).
- BlockQuote
- Block quote element. One or more paragraphs of text attributed
to someone other than the author of the immediate surrounding text.
- Caption
- Caption element. A brief portion of text that describes a
table or a figure.
- Index
- Index element. A sequence of entries that contain identifying
text and reference elements that point out the occurrence of the
text in the main body of the document.
- TOC
- Table of contents element. An element that contains a structured
list of items and labels identifying those items; has its own discrete
hierarchy.
- TOCI
- Table of contents item element. An item contained in a list
associated with a table of contents element.
Table elementsTable elements are special elements for structuring
tables.
- Table
- Table element. A two-dimensional arrangement of data or text
cells that contains table row elements as child elements and may
have a caption element as its first or last child element.
- TR
- Table row element. One row of headings or data in a table;
may contain table header cell elements and table data cell elements.
- TD
- Table data cell element. A table cell that contains nonheader
data.
- TH
- Table header cell element. A table cell that contains header
text or data describing one or more rows or columns of a table.
Inline-level elementsInline-level elements identify a span of text
that has specific formatting or behavior. They are differentiated
from block-level elements. Inline-level elements may be contained
in or contain block-level elements.
- BibEntry
- Bibliography entry element. A description of where some cited
information may be found.
- Quote
- Quote entry element. An inline portion of text that is attributed
to someone other than the author of the text surrounding it; different
from a block quote, which is a whole paragraph or multiple paragraphs,
as opposed to inline text.
- Span
- Span entry element. Any inline segment of text; commonly
used to delimit text that is associated with a set of styling properties.
Special inline-level elementsSimilar to inline-level elements, special inline-level
elements describe an inline portion of text that has special formatting
or behavior.
- Code
- Code entry element. Computer program text embedded within
a document.
- Figure
- Figure entry element. A graphic or graphic representation
associated with text.
- Form
- Form entry element. A PDF form annotation that can be or
has been filled out.
- Formula
- Formula entry element. A mathematical formula.
- Link
- Link entry element. A hyperlink that is embedded within a
document. The target can be in the same document, in another PDF
document, or on a website.
- Note
- Note entry element. Explanatory text or documentation, such
as a footnote or endnote, that is referred to in the main body of
text.
- Reference
- Reference entry element. A citation to text or data that
is found elsewhere in the document.
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