An attribute is an arbitrary key-value metadata pair.

An object associated with a list of attributes.

An audio clip.

Normal body of content.

A footnote at the bottom of a document.

Title of a section.

A bitmap image.

A text element.

Ranged portion of text with associated attributes.

A video clip.

Represents a single semantic content element part of a publication.

An element referencing an embedded external resource.

Represents a purpose of an element in the broader context of the document.

An element which can be represented as human-readable text.