In the "Training" card with the picture of the Rebel sergeant, he's wearing a baseball cap. Do people in the Star Wars Universe wear baseball caps? I have yet to see any of this in Star Wars art.

i assume it would be perhaps an adaption of the imperial officer cap from a local militia? with soo many different systems and their own standing defense force there is certainly room for variation in a rag tag rebellion from those leaving said militias to join up against empire rule

It's just a poorly fitted patrol cap. Pretty much standard military issue.

I'm pretty sure that's a baseball cap... I wouldn't worry about it though. Technically, the blooper on Naboo in Episode II makes Coca Cola bottles canon too...