Clearing contextual recents dock menu?

OK. I found part of the answer. The list of recent documents is contained in ~Library/ Application Support/ com.apple.sharedfilelist/ com.apple.LSSharedFileList.ApplicationRecentDocuments/ org.libreoffice.script.sfl2 ("org.libreoffice.script" is the bundle identifier for the app; for other apps use their bundle identifier.) Deleting that file will clear the list of recents, but you have to log out of your account for it to take effect -- presumably Dock info is cached in some account-local data that isn't erased with a reboot, safe or normal. What is interesting is that the Dock's recent-file-list uses some kind of universal file I.d. -- if you change the name of the file, the Dock's list will still find the file -- but the recents list in the app won't. Note that deleting the file will clear the recents list in the Dock, but not the one in the app. At least that's the case for LibreOffice.

Nope, LibreOffice doesn't have that option in the contextual menu. I did find a file under com.apple.LSSharedFileList.ApplicationRecentDocuments, which is apparently where the recents list is kept, for LibreOffice and deleted it, killed and restarted the Dock, and it didn't make any difference. The app itself, since I just reinstalled it, has no recents list of its own -- but there still is a complete (10 items) one in the dock contextual menu. I've even done a safe boot in case this stuff is buried in a cache somewhere, but that didn't help either. There must be a hidden database somewhere, but I haven't been able to find any mention of it! I don't know if this is an OS bug or an app bug, but it sure is annoying, in a petty sort of way.