My legal experience is limited to a year at law school and working for a law firm for a couple of years. Hardly anything to write home about! I just wanted to get the opinion of someone I know and trust, just in case I am doing something wrong. Which it seems I'm not.
Bose, the annotation I mentioned IS the signature and licence number. I don't sign logbooks unless there is a reason for it, such as for the "training flight". All other signatures for training courses are dealt with by the use of a stamp and signature at the end of a course as I've already mentioned.
Signing every line of a logbook makes it look awfully messy and is simply unnecessary. All entries are checked against records to ensure that they match up, in goes the stamp and off goes the book to either the Belgrano or to the examiner to sign the form.
A simple process really and one that seems to work fairly well in a busy club environment. As you fly with individuals more, a different system may work better for you. This one works well for me and how we do things. No-one has ever complained and there has never been an issue of any kind, whereas I have seen plenty of mistakes where logbooks have become overcrowded with signatures (especially for people who have flown in the states a lot) where signatures have appeared on the wrong lines, are unreadable or they simply take up so much space that the comment box hasn't got room to annotate what the flight was for.
I think the way we do it, is far more elegant, but horses for courses.