Document
| Description | Represents the root element of a PDF's logical structure tree. It serves as the container for all content elements, defining the primary organizational hierarchy of the document. |
|---|---|
| Namespace | 1.7 2.0 |
| Category | document grouping |
Attributes
Specifies how the element is placed relative to surrounding content (e.g., block-level or inline flow).
Defines the direction of text flow (e.g., left-to-right, right-to-left, or vertical).
Sets the background color for the element’s content area.
Specifies the color of the border around the element.
Indicates the style of the border (e.g., solid, dashed, dotted).
Defines the thickness of the border line in user space units (such as points).
Determines the space between the element’s border (or boundary) and its inner content.
Applies the primary color (fill or stroke) for the text or graphic content.
Main indicator of type. This semantic association allows tools to present and support interaction with the object in a manner that is consistent with user expectations about other objects of that type.
Properties
A unique identifier for this structure element, used for referencing it from other elements or external sources.
Defines or references the lower-level PDF objects (content items) that represent the actual text or graphic content of this element.
An attribute dictionary providing additional layout or semantic attributes for this element. May reference a class map.
An array of class names associated with this element, which can link to further style or attribute definitions in a class map.
An optional text label or title for this structure element—can serve as a short descriptor (e.g., for a heading).
Identifies the primary language for the text in this element (e.g., 'en-US'), aiding in proper text processing and accessibility.
Provides alternative text describing the element’s content, primarily for accessibility (screen readers).
Contains expansion text used to clarify abbreviations, acronyms, or symbolic content within the element.
Gives an exact text equivalent for non-textual or symbolic content, allowing screen readers to read it as plain text.
An array of associated files or file specifications that relate to this structure element (e.g., attachments).
Specifies a namespace identifier for custom attributes, enabling extensibility without conflicting with standard keys.
Indicates the phonetic alphabet used for any phonetic text within the element (e.g., IPA).
Contains the phonemic representation of text for pronunciation guidance or linguistic analysis.
Differences
Well tagged PDF:
Well-Tagged PDF provides detailed guidelines for document structure elements—such as Document, Part, Art, Sect, Div, and others—to ensure semantic clarity and reusability. It emphasizes clear nesting and explicit tagging of structural elements.
Requires a well-defined structure tree with proper role mapping, explicit tagging for headings and sections, and consistent application of element boundaries to support both reusability and accessibility.
PDFUA:
PDF/UA (PDF/UA-1 and PDF/UA-2) mandates a complete and accessible logical structure tree. It ensures that all document structure elements are tagged in a way that assistive technologies can interpret, enhancing the document’s accessibility.
Mandates inclusion of all essential structural elements with correct role mapping, proper tagging of headings, lists, tables, and alternative descriptions where needed, ensuring content is accessible to users with disabilities.
Use cases
Tag Relationships
Click on any tag to view its details.
Related Matterhorn Protocol checkpoints
Examples
- A mail merge PDF typically contains a number of letters to different recipients. This implies that the PDF at the top level is one document, containing multiple documents at its child level where each such document is a letter to a recipient.
- A mail merge PDF typically contains a number of letters to different recipients. This implies that the PDF at the top level is one document, containing multiple documents at its child level where each such document is a letter to a recipient.