why not just carry a copy of the "permitted/prohibitted" list from the tsa website and simply show the agent that matches (up to 4 books) are allowed in carry on but not checked luggage. it worked for me and when asked why i travel with a copy of the list, i simply informed the agent (and supervisor) that it was exactly for this purpose-to train when there are "inconsistencies and irregularities".

main page:
http://www.tsa.gov/public/interapp/e...orial_1012.xml

link to "permitted/prohinited" list:
http://www.tsa.gov/public/interweb/a...ited_Facts.doc