When having an identity column is not a good idea?

Question

In tables where you need only 1 column as the key, and values in that column can be integers, when you shouldn\'t use an identity field?

To the contrary, in

Answer 1

I suppose if you are creating a many-to-many linking table, where both fields are foreign keys, you don't need an identity field.

Nowadays I imagine that most ORMs expect there to be an identity field in every table. In general, it is a good practice to provide one.