Miscellaneous elements

Most DITA elements represent discourse, or information that is placed exactly as entered. However, there are also types of information that are usually authored in context with a thought or issue, but upon output, the content might be relocated, suppressed, or used only for purposes such as inline annotations for drafts. These elements include footnotes, index entries, draft comments, and special cleanup containers that can hold migrated data that still needs a writer's intervention to get into the right place.

draft-comment
The <draft-comment> element allows simple review and discussion of topic contents within the marked-up content. Use the <draft-comment> element to ask a question or make a comment that you would like others to review. To indicate the source of the draft comment or the status of the comment, use the author, time or disposition attributes.
fn
Use footnote (<fn>) to annotate text with notes that are not appropriate for inclusion in line or to indicate the source for facts or other material used in the text.
indexterm
An <indexterm> is an index entry. You can nest entries to create multi-level indexes. The content is not output as part of topic content, only as part of the index.
indextermref
An <indextermref> is a reference to an index entry in a lookup table used by the indexing process. If you want to create index markers pointing to referenced items, but only want page numbers instead of separate index entries to be generated, use the index term reference <indextermref> element. This adds the page number of the reference to the index without creating a separate index entry.
tm
The trademark (<tm>) element in DITA is used to markup and identify a term or phrase that is trademarked. Trademarks include registered trademarks, service marks, slogans and logos.