Total posts : 45366
Here is a cut from the FCC rules:
CHAPTER I–FEDERAL COMMUNICATIONS COMMISSION
PART 73_RADIO BROADCAST SERVICES
Sec. 73.3550 Requests for new or modified call sign assignments.
(l) Users of nonlicensed, low-power devices operating under part 15 of this chapter may use whatever identification is currently desired, so long as propriety is observed and no confusion results with a station for which the FCC issues a license.
I think that makes it pretty clear! Just don’t use your local stations call sign or make statements that would make it seem you are a station licensed by the FCC.