You lost me here. I'll deal with this first, because I think it'll tidy up some of the misunderstandings that've been flying around in this thread. A fairly venerable term for this second sort of usage is 'essence'. Still, like most things philosophical, it's swings and roundabouts, and they're coming back into fashion. OK, so I take identity to be a relation.
Identification is a different kettle of fish altogether.
It's about how you come to know that the thing picked out by one description is identical to the thing picked out by another. Unlike identity, which just does it's thing, identification is problematic, because it requires an identifying agent of some sort, and most identifying agents are fallible. OK, I think that if you replace 'identity' with 'essence' or 'gestalt' then we're probably in synch. Trouble is, I think your chances of getting anywhere with defining the essence of a web-site are likely to be very slim indeed. I've no idea.