What stops me from showing up to formation after I'm out?

Say hypothetically, I'm just bored. Needing something more in my medically retired life. Upon a whim, I decide to show up to some random formation. Could be in OCPs, could be in PTs, hell maybe I'll get a set of tiger stripe just to stand in. What's really the worst the happens?

I'll just have a caniac combo with a lemonade please. What do you mean this is a Wendy's?

Edit: I'm not actually going to do this. I had a random idea, and I thought it was a funny. Just a shitpost guys