Categories whose existence is real. E.g. - Jīva
(soul), Ajīva (non-soul) etc...
tathyāḥ avitatliā ninipacaritavṛttayaḥ.
(UśāVṛ Pa 562)
jīvājīvā ya baṃdho ya, puṇṇaṃ pāvāsavo tahā. saṃvaro nijjarā mokkho, saṃtee tahiyā nava..
(U 28.14)
See - Tattva.