-------- Original Message -------- Subject: TPC, JNC editions Date: Wed, 19 Jan 2005 14:54:59 -0500 From: Michael Fry <[log in to unmask]> Organization: UMD Libraries To: Maps and Air Photo Systems Forum <[log in to unmask]> ------------------ We have what look like two versions of some TPC and JNC charts, but it's not clear to me if I should keep both. For example, we have TPC K-10CG (1975) and TPC K-10C (2001), as well as JNC-7N (1975) and JNC-7 (1998). Are these simply different editions of the same chart (with slightly different names), or substantively different charts? Thank you. mf -- Michael Fry Government Documents & Maps Librarian University of Maryland Libraries