As I see it, type of material is a form or genre and so should go into 655. Genre Headings for Fiction http://www.lcls.org/content/cataloging/general/genre_headings.pdf is a short introduction. I have used AAT http://www.getty.edu/research/conducting_research/vocabularies/aat/ terms and the Thesaurs for Graphical Materials http://www.loc.gov/rr/print/tgm2/ Sincerely, David Bigwood bigwood@lpi.usra.edu Lunar & Planetary Institute http://www.lpi.usra.edu/library/whats_new.shtml Cataloging News http://www.catalogablog.blogspot.com 5. " type of material (novel, screenplay, poem, etc: not the regular MARC types) ..." In the few cases where I've seen this done -- and I do think it can be very helpful as the GMD and even SMD categories aren't often clear enough for people and the actual coding for these aspects is limited to a near-dozen encoded categories in position 33 of the 008 field (for book materials anyway)-- it was **simply with a 500 note.** Again, you could get fancier and prescribe a local use for one of the 59x notes. I think I've also seen 653 used for this function. You could also probably use the 655 for your added types of materials. 6. "... genre ..." 655 is for Index Term--Genre/Form, so genre should go here. (I don't think I've ever seen it used for Form though)