What does BYF stand for?

Barium Yttrium Fluoride (UWER)

Bete - Language code (ETLW)

Bloody Young Fool - Officer under the age of 30 - British (DSUE)

Boyne Falls, MI - Amtrak Busline code

Davis Fiberglass, Havre de Grace, MD - Manufacturer code for watercraft hull identification number (USCG)