The <bodydiv> element is intended to be used as a grouping element for containing logical blocks of info that otherwise do not need either a title or a separate topic. It can be placed only within a <body> or within another <bodydiv>.
The <sectiondiv> element is similar to the <bodydiv> element except that it has more container elements - it can be placed within a <section>, <sectiondiv>, and a bunch of other tags depending upon the topic type.
Why and when should I use <bodydiv> and <sectiondiv>If I want to reuse a whole group of info somewhere else, these two tags are handy. Not that such reuse couldn't have been done otherwise, but then, these tags can, for example, contain several <p> elements, some lists, some images...it's almost like being able to reuse an information chunk instead of individual tags. Without being actual formal topics, these tags behave like topics.
Related informationThe <concept> topic type also has a new element in v1.2 that's similar to <bodydiv> and <sectiondiv>. It's called <conbodydiv>.
History of <topic> elementsHere's a list of the various topic elements from v 1.0 to 1.2:
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