The feature to place multiple bib-level holds for a single patron that was added in bug 14695 doesn't seem to be mentioned in the manual. It would be helpful to have a note about it in Circulation/Holds/Placing holds in the staff interface, and in the page on Circulation and Fines rules, since the "Holds to place (count)" textbox only appears if the circulation rules allow more than 1, but fewer than Unlimited, holds per record for that patron type.
Merge request submitted https://gitlab.com/koha-community/koha-manual/-/merge_requests/696