(philosophy) The principle that, if two objects are indistinguishable from one another with respect to all of their properties, then they are identical.

(US, Canada, law) A government regulation establishing the criteria which must be met before a product may be labeled as being a certain food.

plural of standard of identity

plural of identity card

plural of identity theft

A card or badge showing the official identity of the bearer.

One's identity on an electronic or digital system such as the Internet.

(psychology) The age category such as "child", "young adult", "old person", etc. that is part of a person's self-identity.

(category theory) A functor from a category to itself which maps each object of that category to itself and each morphism of that category to itself.

(category theory) A unique morphism corresponding to each object of a category, which has its domain equal to its codomain, and which composed with any morphism (with which it is composable) gives that same morphism.