Full Idea
What we might call 'identity criteria' associated with a name such as 'Aristotle' are what the users of the name regard as essential and established facts about him.
Gist of Idea
The 'identity criteria' of a name are a group of essential and established facts
Source
Alvin Plantinga (World and Essence [1970], I)
Book Reference
Plantinga,Alvin: 'Essays in the Metaphysics of Modality' [OUP 2003], p.50
A Reaction
The problem here is that identifying something is superficial, whereas essences run deep. Plantinga is, in fact, talking about Lockean 'nominal essence' (and seems unaware of the fact, and never mentions the Lockean real/nominal distinction).