2.2.1.7 Topic content

The content of all topics, regardless of topic type, is built on the same common structures.

Topic body
The topic body contains all content except for that contained in the title or the short description/abstract. The topic body can be constrained to remove specific elements from the content model; it also can be specialized to add additional specialized elements to the content model. The topic body can be generic while the topic title and prolog are specialized.
Sections and examples
The body of a topic might contain divisions, such as sections and examples. They might contain block-level elements like titles and paragraphs and phrase-level elements like API names or text. It is recommend that sections have titles, whether they are entered directly into the <title> element or rendered using a fixed or default title.
Either body divisions or untitled sections or examples can be used to delimit arbitrary structures within a topic body. However, body divisions can nest, but sections and examples cannot contain sections.
<sectiondiv>
The <sectiondiv> element enables the arbitrary grouping of content within a section for the purpose of content reuse. The <sectiondiv> element does not include a title. Content that requires a title should use <section> or <example>.
<bodydiv>
The <bodydiv> element enables the arbitrary grouping of content within the body of a topic for the purpose of content reuse. The <bodydiv> element does not include a title. Content that requires a title should use <section> or <example>.
<div>
The <div> element enables the arbitrary grouping of content within a topic. The <div> element does not include a title. Content that requires a title should use <section> or <example> or, possibly, <fig>.
Block-level elements
Paragraphs, lists, figures, and tables are types of "block" elements. As a class of content, they can contain other blocks, phrases, or text, though the rules vary for each structure.
Phrases and keywords
Phrase level elements can contain markup to label parts of a paragraph or parts of a sentence as having special semantic meaning or presentation characteristics, such as <uicontrol> or <b>. Phrases can usually contain other phrases and keywords as well as text. Keywords can only contain text.
Images
Images can be inserted to display photographs, illustrations, screen captures, diagrams, and more. At the phrase level, they can display trademark characters, icons, toolbar buttons, and so forth.
Multimedia
The <object> element enables authors to include multimedia, such as diagrams that can be rotated and expanded. The <foreign> element enables authors to include media within topic content, for example, SVG graphics, MathML equations, and so on.