Two marks carry a revision with its author and date: an insertion is
marked text, a deletion is text kept and struck through. Consecutive
typing joins one change; accept/reject work at the cursor or on all.
ODF splits the pair — text:change-start/-end around an insertion, a
text:change where a deletion was, its text in the tracked-changes
registry. DOCX uses w:ins/w:del with w:delText. Both round-trip, and
accepting every change gives the document an unrecorded edit would.