The ANO wording is "navigation charts or codes appropriate to the intended flight". So you can use whatever you want as long as you can convince the powers that be that it was appropriate. I don't fancy my chances if I bust the Stansted CTA with only a Little Chef locations map on board though...
H
Edit to add: sorry for raising this really, but its a bit of a hobby horse of mine - too many folk just stick to the most recent issue of the half-mil (oh that's OK, I'm legal) without thinking for themselves what they actually need for the intended flight. The ANO wording places the responsibility with the pilot, which is as it should be. H