A C&R license is a FFL for collectors of Curio & Relic firearms, very good examples are the SKS, the Moison Nagant, the Mauser rifles, most antique firearms. It is a Federal Firearms License, but its for the collector, you can't use it for a business, strictly for the individual, it allows you to order antiques that are on the C&R list directly from the importers, you don't need to have a qualifying firearm transferred through a dealer. It also gets you discounted prices on many items from Midway, Brownells, and Grafs. It costs $30 for the C&R and it lasts 3 years.
Here's more info:
http://www.surplusrifle.com/shooting2005/h...ffl03/index.asp
With a C&R you can order qualified arms from Century, AIM, SOG and a lot of other surplus dealers, as an example, go to AIM's website, click on the used and surplus firearms, then look for the listings with the C&R logo, those are the qualifying arms.
http://www.aimsurplus.com/
http://www.southernohiogun.com/surrifle.htm