Below are 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.
Container elements are the highest level of element and provide hierarchical grouping for other block-level elements.
Document element. The root element of a document’s tag tree.
Part element. A large division of a document; may group smaller units of content together, such as division elements, article elements, or section elements.
Division element. A generic block-level element or group of block-level elements.
Article element. A self-contained body of text considered to be a single narrative.
Section element. A general container element type, comparable to Division (DIV) in HTML, which is usually a component of a part element or an article element.
Heading and paragraph elements
Heading 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 (H1to H6) are available for applications that don’t hierarchically nest sections.
Label and list elements
Label and list elements are block-level elements used for structuring lists.
List element. Any sequence of items of similar meaning or other relevance; immediate child elements should be list item elements.
List item element. Any one member of a list; may have a label element (optional) and a list body element (required) as a child.
Label element. A bullet, name, or number that identifies and distinguishes an element from others in the same list.
List item body element. The descriptive content of a list item.
Special text elements
Special text elements identify text that isn’t used as a generic paragraph (P).
Block quote element. One or more paragraphs of text attributed to someone other than the author of the immediate surrounding text.
Caption element. A brief portion of text that describes a table or a figure.
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.
Table of contents element. An element that contains a structured list of items and labels identifying those items; has its own discrete hierarchy.
Table of contents item element. An item contained in a list associated with a table of contents element.
Table elements are special elements for structuring tables.
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.
Table row element. One row of headings or data in a table; may contain table header cell elements and table data cell elements.
Table data cell element. A table cell that contains nonheader data.
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 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.
Bibliography entry element. A description of where some cited information may be found.
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 entry element. Any inline segment of text; commonly used to delimit text that is associated with a set of styling properties.
Special inline-level elements
Similar to inline-level elements, special inline-level elements describe an inline portion of text that has special formatting or behavior.
Code entry element. Computer program text embedded within a document.
Figure entry element. A graphic or graphic representation associated with text.
Form entry element. A PDF form annotation that can be or has been filled out.
Formula entry element. A mathematical formula.
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 entry element. Explanatory text or documentation, such as a footnote or endnote, that is referred to in the main body of text.
Reference entry element. A citation to text or data that is found elsewhere in the document.