Let me write down everything I understand first.
I know that dhammā(kamma viññāṇa) belongs to viññāṇa dhātu(or nāmalōka) and also is rūpa. Further, vedana, saññā, saṅkhāra, and viññāṇa belong to viññāṇa dhātu but aren’t rūpa too.
I know that vedanakkhandha, saññākkhandha, saṅkhārakkhandha, and viññāṇakkhandha are preserved permanently in nāmalōka, but rūpakkhanda are not. And I don’t know why rūpakkhanda can not be preserved even though it is mental. (I wonder why this is.)
Lal said: “Only dhammā below the suddhāṭṭhaka AND namagotta (memory records) belong to viññāṇa dhātu.”
Okay. So everything I wrote above(except rūpakkhanda) belongs to one of these two categories(“dhammā below the suddhāṭṭhaka” and “namagotta”). Right? Did I miss anything?