defHints work as a bitmask. To combine them, add their numerical values together.

Internal Constant Name Bit Mask Notes
CDEF_HINT_PERSONA 1 Player characters only.
CDEF_HINT_COPPER_SHOPKEEPER 2 Standard vendor minimap icons and interacts.
CDEF_HINT_CREDIT_SHOPKEEPER 4 Doesn't seem to be used.
CDEF_HINT_ESSENCE_VENDOR 8 All chests which trade tokens or essences for loot.
CDEF_HINT_QUEST_GIVER 16 Must be set on any NPCs that give quests, otherwise the icon won't show. Keep this in mind if making quests for new NPCs.
CDEF_HINT_QUEST_ENDER 32 It's used, but not sure if technically needed.
CDEF_HINT_CRAFTER 64 For crafting of weapon/armor plans. See the TRANSFORMER status effect for refashioners.
CDEF_HINT_CLANREGISTRAR 128 Clans are currently not implemented.
CDEF_HINT_VAULT 256 Item vault. Definition present from 0.8.6+
CDEF_HINT_CREDIT_SHOP 512 Not used in the official creature list. Definition present from 0.8.6+