This page categorizes all moves that are not coded or that do not work correctly. These includes moves with no functionality, moves that deal damage but that does not have the secondary effect or mechanic they should have in the original games, and moves which have bugs causing significant changes to its usability. Moves that have minor bugs are not listed.
Each move in the list has their own section on their page that describes the content of their bug. They may also have a link to a report thread of the bug if one exists.
If you intend to deploy one of these moves in PvP, ensure that you acquaint yourself with the PvP Rules to ascertain that you are not using a move that is codified against the PvP rules; otherwise, you may be penalized with account repercussions.