Non-deployed Marines and sailors assigned to Marine Corps units no longer can wear anything other than appropriate seasonal service uniforms to work, as of Jan. 4. The directive, issued in November by Commandant Gen. James F. Amos, effectively puts an end to “Casual Friday” for these Marines and sailors. The Army, Navy and Air Force have implemented no such policies. But Air Force Chief of Staff Gen. Mark A. Welsh III recently did away with the “Blues Monday” rule, which required airmen to wear their blue uniforms rather than khakis to work. Former chief of staff Gen. Norton A. Shwartz instituted “Blues Monday” in 2008, to reconnect airmen with a sense of the service’s image and culture.