What used to piss me off was songbooks in which people would put down the actual chords without mentioning the capo.

You'd break your fingers trying to play the damn stuff in silly keys, and then you'd see them on a stage or on the box, and finds they were just playing easy stuff with a capo.

Strictly speaking Rick is right. But I'd just put at the top "C chords, but I'd probably sing it it Eb with the capo on the third fret".

Actually it's not just with difficult keys that this comes in - you might be singing something in a key where the chords are perfectly straightforward, but the accompaniment you want just sounds better with different chord chapes and a capo.