Remove Before Flight
Or don’t.
Equipment used in aviation and spaceflight often has a temporary cover, alignment fixture, or restraining pin to protect it during storage. Forgetting to remove these pieces could bring disastrous results, so they are painted or flagged with bright red or yellow colors and stenciled with the warning, “REMOVE BEFORE FLIGHT.” Pilots and ground crews check and recheck these items to ensure they are removed. Every so often, though, a mistake is made and one of these items is still in place during a flight. The responsible party gets appropriately razzed, which usually costs them a round of beverages at the next social gathering.
Recently I was performing maintenance that required opening an obscure space station panel, one that probably had not been opened since this module was launched. Inside I found a piece of hardware sporting a bright yellow REMOVE BEFORE FLIGHT tag. It was just a tag with no cover or fixture, so it didn’t really matter. I took a picture of it and left the tag as a surprise for the next person who wanders this way.