front brake hose question

Just had a quick question cause I'm curious about the front brakes hoses on a 72 demon w/73+ disc brakes.

On the end of the brake hose that connects to the brake line, there is a C clip just before the end around the connector. On my new ones that aren't installed yet, the clip is loose and just spins around, but tight on the ones already on my car.

I'm just curious as to what its purpose is? The way it looks it doesn't really seem like it does anything or secure anything. Does it have to be removed in order to take the old one off or what?

Maybe a stupid question but oh well