On some DVD’s, there are multiple menu animation and sets (I think the most famous DVD’s for this are the Star Wars DVD’s), which is randomly chosen each time you play the DVD. How do you only keep one of these?
If in different language units, use PgcEdit to remove the LU.
If you want to remove the random selection of a menu set, again with PgcEdit, find the RND command and substitute a command which picks the menu set you want. Or follow the procedure in the next paragraph.
If you have, for example, 3 languages (or menu sets), all in the (en) language unit, you can, using PgcEdit, assign the corresponding English VCIDs for each of the foreign VCIDs in each PGC that has video in it. Or just delete them cos they will never be played anyway (unless your player is set up to play a different language).
In all cases, clean up the (now) unreferenced material afterwards with FixVTS.