add me to the anti mixup crowd. Like I mentioned in the other thread, a table of 8 and a 3 year old kleptomaniac make identification a nessesity. The group has such a mixed bag of books that it is almost impossible by the end of a session to figure out who's is who's. We buy books based on what catches our eye and as such have ended up with a large and miandering library. I use a labelmaker to put my name along the spine and the inside cover. I got paper for it that looks like vellum so it doesn't destroy the look of the book and though the label on the spine tends to fall off after a bit I just relable after a while. I rarely mark up my older books, though they tend to be an uncommon enough fixture at the table that no one usually needs to ask who the 1st ed Dieties and Demigods or A Guide to the World Of Greyhawk vol III belongs to.