For my first civvy instructor job, I wore clean presentable clothes. The flying was fun, and we did not pretend to be like Capt Stubings (the Luuuuve Boat).
The next school I worked for, I was given two striper epps. The CFI (the only other pilot) wore four stripes.
The aircraft were small single engine funships.
Still after all this time, the significance of the stripes eludes me. Is there a formal standard?