Identifying nitrate negatives

I am a conservation technician at the New-York Historical Society
who is working with the nitrate sheet film in the collection.
Presently I am trying to separate nitrates from the main collection.
The best identification I have found are notch code guides. I am
stumped with some notch codes and was wondering if anyone had any
recommendations of where to look for more guides or what these codes
could be. I don't think the film I am stumped with was manufactured
by Kodak. I can send pictures of the codes to anyone interested.
Notch code Guides I have already consulted John P. McElhone's Guide
(National Gallery of Canada) from the Photographic Materials Group
Winter Meeting, San Francisco, 7-8 February, 1997 and
Fort Lewis College Center of Southwest Studies'
"Photonegatives identification tips"
<URL:http://swcenter.fortlewis.edu/tools/NegsID.htm>

Leslie Augenbraun
Conservation Technician
New-York Historical Society
170 Central Park West
New York, NY  10024
212-485-9290


                                  ***
                  Conservation DistList Instance 18:42
                  Distributed: Friday, March 11, 2005
                       Message Id: cdl-18-42-042
                                  ***