FIB is a term I only seen when joining online communities FIB equated to woman identified butch... There seemed to be a need to separate them from MIB (male identified butch). What I mean by separation is online there seemed to be this need to distinct one from the other. I had a hard time learning the verbiage since where I came from or grew where butch equated woman period.
I think the internets introduced us to many gender, label, identity forums discussions and threads such as this. It's a hard road when dealing with all the new verbiage out there and yes sometimes it feels we (women) are continuously put in the back burner. I think threads like this and the discussions being had will not let that happen