<DD>

Usage Recommendation
use it if you use <DL ...>

<DD> sets the description part of a term/description pair in a definition list.

this code	produces this
<DL> <DT>flame <DD>an ugly argument in a newsgroup <DT>spam <DD>annoying unrequested email <DT>troll <DD>someone who start flames by posting stupid things </DL>	flame an ugly argument in a newsgroup spam annoying unrequested email troll someone who start flames by posting stupid things

Although it is acceptable to put a </DD> at the end of the element, the end tag is not required and is rarely used.