Oh OK. I`ve never bothered with them (I just keep the receipts) but when my car had a 10,000 mile service the other week the garage told me they had "stamped the book" which must have been in the manufacturers info in the glove compartment
....because you have a print-out of the service performed and a matching invoice....just no rubber stamp in a little book.
Don't blame me, btw, that's just the way they're doing things now...