The only useful addition to the title 'folk' is a regional adjective like Irish, Appalachian, Chinese etc. This'll tell tell you most of what you need to know! The Aran sweaters were only ever worn by the Clancy brothers about 35 years ago, although there are still a lot of beards about (including mine, but I am a banjo player). People who like the music won't mind it being called folk, and people who don't don't matter (tee hee).
Cheers
Ray