Discriminator

Method of distinguishing elements with the same identifier in computing

In computing, a discriminator is a field of characters designed to separate a certain element from others of the same identifier. As an example, suppose that a program must save two unique objects to memory, both of whose identifiers happen to be foo. To ensure the two objects are not conflated, the program may assign discriminators to the objects in the form of numbers; thus, foo (1) and foo (2) distinguish both objects named foo.

This keyword could refer to multiple things. Here are some suggestions: