An old-timer PFC in a unit failed to notice a passing second lieutenant who was obviously a newcomer to both the service and the unit.
The shavetail stopped and angrily demanded to know why he hadn't been saluted.
"Because-ah, it's Tuesday, sir," the PFC replied, thinking fast. "Saluting isn't required anymore. There was a new garrison regulation last week. No 847-5, I think. It's an attempt to promote greater understanding between the ranks."
Embarrassed by his apparent ignorance of local customs, the lieutenant mumbled a brief thanks and hurried on his way.