DAN has nothing to do with Danbury Pharm.

Dan is simply the city in which the watson plant manufactures the generic solid dose drugs

http://www.watsonpharm.com/location_detail.asp?node=career&loc=7&page_type=HTML

DAN is short for Danbury, CT

This location makes many of the generic doses. All generics manufactured from this location are stamped "DAN"

Watson makes many others in their Corodo, California loccation.