I'm going to throw a wrench into the discussion that some will find difficult to swallow, and others will find relief!
Our troop has made this definition:
The troop has determined due to cost amongst other factors that clean normal fitting blue or black jeans are the apporpriate pants to wear, scout pants or shorts are also welcomed, but not required. Participation in District Council or National training, activities such as jamborees, camporalls, require a full scout uniform (khaki shirt, olive pants, socks, neckerchief, slide)
Class A - Khaki shirt with Sash required for Board