Item identification is working oddly, two examples:

I found a multi-colored cloak and equipped it, it turned out to be an uncursed cloak of adornment [+0,+0], {Ap+4}. When looking at the item discoveries the character has made ("/" -command), there can be seen that multi-colored cloak is identified as cloak of adornment. After a while, i found two more of multi-colored cloaks - the character did not seem to know that i had already identified this cloak. One of these two was {Ap+5} and the other was exactly the same as the first, except it was blessed. It seems that when identifying (either by equipping or via a scroll) an item, only the exactly same item is known, status and statwise (B/U/C, stats).

Other time i found a leather girdle and equipped it, it was an uncursed girdle of carrying [+0,+0]. A while after that i found another one on the ground and standing on top of it even without picking it up it was identified as the same - the character somehow knew the stats [+0,+0] without even picking it up.

To me it sounds that something is not working right. In my opinion, item types (for example cloak of adornment, defence, protection etc.) should be identified as the item appearance is known (multi-colored etc.). Also, the stats (DV, PV, +Ap etc.) should not be known until equipped / identified. And also, the B/U/C -status affecting if the item known or not seems weird. This leads to the situation that one knows that yes, that multi-colored cloak on the ground is a cloak of adornment, but it is somehow different than the one i have currrently equipped - if one checks the discoveries for item appearances known or remembers seeing that one before.