Full Idea
In this consists identity, when the ideas a thing is attributed to vary not at all from what they were at that moment, wherein we consider their former existence, and to which we compare the present.
Gist of Idea
Identity means that the idea of a thing remains the same over time
Source
John Locke (Essay Conc Human Understanding (2nd Ed) [1694], 2.24.01)
Book Reference
Locke,John: 'Essay Concerning Human Understanding', ed/tr. Nidditch,P.H. [OUP 1979], p.328
A Reaction
Since we recognise that we might, in odd circumstances, have the identical idea while the object has been swapped, this is wrong. It sounds like the identity of indiscernibles. Identity is a concept applied to reality, not to ideas.