Caption

Description	Specifies a caption or title for an element such as a figure or table, providing a brief description of its content.
Namespace	1.7 2.0
Category	grouping block

Attributes

Placement

Specifies how the element is placed relative to surrounding content (e.g., block-level or inline flow).

WritingMode

Defines the direction of text flow (e.g., left-to-right, right-to-left, or vertical).

BackgroundColor

Sets the background color for the element’s content area.

BorderColor

Specifies the color of the border around the element.

BorderStyle

Indicates the style of the border (e.g., solid, dashed, dotted).

BorderThickness

Defines the thickness of the border line in user space units (such as points).

Padding

Determines the space between the element’s border (or boundary) and its inner content.

Color

Applies the primary color (fill or stroke) for the text or graphic content.

BBox

Width

Declares an explicit width for the element in user space units.

Height

Declares an explicit height for the element in user space units.

role

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

Lang

Properties

Identifies the primary language for the text in this element (e.g., 'en-US'), aiding in proper text processing and accessibility.

Differences

Well tagged PDF:

The 'Caption' element in Well-Tagged PDF provides a title or summary for a table, offering context and a brief description.

It must be clearly linked to the table it describes and be positioned appropriately within the structure tree to support content extraction.

PDFUA:

In PDF/UA, the 'Caption' element is essential for accessibility as it gives users an overview of the table's purpose and content.

Each table should include a 'Caption' element that is clearly tagged and associated with the table, ensuring that assistive technologies can present this summary to users.