I've been using the acronym 'UAT' for User Acceptance Tests to describe automated tests that capture required application behaviour. But while terms like 'unit tests' are relatively well defined UATs is not widely a recognised acronym. Tongiht while updating NUnitGridRunner documentation I came accross a site describing Acceptance Test Driven Development with the aconym 'ATDD'. I find the diagram on this page complelling and I'm now thinking of hanging my hat on the ATDD acronym even though it is not a three letter acronym (TLA).
Check it out here. Although when reading substitute 'Agile' for 'XP'.