Content gap
A content gap is a question your users need answered that your site does not answer, surfaced by the feedback, searches, and support tickets that keep asking for it.
In a feedback context the gap arrives already worded by the person who has it. A comment saying "this does not say which permissions the token needs" is not an opinion, it is a specification for a missing paragraph, filed against the exact page where the paragraph belongs. Collected per page, those comments name both the gap and its location at once.
Gaps are not always missing pages. A page can exist and still register as a gap because it is unfindable from where the reader started, buried under a heading that describes something else, or stale enough that readers stopped trusting it. The fix is often a link, a heading, or a rewrite rather than a new page, and treating every gap as a writing assignment inflates the backlog for no reason.
Ranking the gaps is what makes the list useful. Frequency multiplied by page traffic beats intuition, and the pages collecting the most negative ratings per visit are where the next week of work goes. Any other ordering is a guess about which chapter to write next.
Frequently asked questions
How do you find content gaps on a documentation site?
Read the per-page feedback comments, the on-site searches that returned nothing, and the support tickets that repeat. Feedback comments are the most direct source, because they are the words readers chose, attached to the page that failed them.
Are content gaps the same as keyword gaps?
No. A keyword gap is a query competitors rank for and you do not, which is an acquisition problem. A content gap is a question your existing users asked and you did not answer, which is a support and retention problem.
Who should own closing content gaps?
Whoever owns the page. Gaps that get routed to a general backlog stall, because nobody in that backlog knows the subject well enough to write the missing paragraph.