Patch history tables in Oracle Apps

AD_APPL_TOPS - Stores information about all APPL_TOPS utilizing this instance.
AD_APPLIED_PATCHES - Stores information about all distinct updates applied.
AD_BUGS - Stores information about all distinct bug fixes applied.
AD_DRIVERS - Stores information about the drivers that comprise an update.
AD_FILE_VERSIONS - Stores version information for files.
AD_FILES - Stores information about files in the system.
AD_PATCH_COMMON_ACTIONS - Stores information about actions in update driver files.
AD_PATCH_DRIVER_LANGS - Stores information about the languages included in an update driver file.
AD_PATCH_DRIVER_MINIPKS - Stores information about minipacks.
AD_PATCH_RUN_BUG_ACTIONS - Stores detailed information about actions applied by an update.
AD_PATCH_RUN_BUGS - Stores information about all bug fixes included in an update , applied or not.
AD_PATCH_RUNS - Stores information about all incvocations of AutoPatch for all of the various updates applied.
AD_RELEASES - Stores release information about the Oracle Applications system.

References:
http://appsoracle.blogspot.ca/2012/03/patch-history-tables-in-oracle-apps.html