BF ceratianly stands for the Belleri company,but I'v never seen a translation of the "F". It could mean either France or Freres as has been mentioned. The company is based about 5 miles outside St Etienne in the hill top village of Sorbiers..not too far from where the old and former Cyclo works once stood.
The company was still in business, or at least was, two years ago when I called in. In fact there seemed to be new buildings in the course of erection. The company does very very little work for the cycle industry these days, but has developed very good plating plants and tube manipulation workshops..so they have diversified to stay alive. I called way back in about 1997/98..perhaps even 2001 in order to buy a set of bars and stem for a 1993 TVT carbon frame I wanted to build up with 100% French equipment. The company had developed a very attractive range called "Star-Line" or something like that ,that boasted beautiful shades of tungsten grey anodising, with the engraved name and features eg height scale, highlighted in white. I still have the bars on the bike...extremely elegant. It's just a pity that the St Etienne..and the French bike industry..crumbled like it did. However..(This is off-topic) there is framebuilder in Lyon who is tigging together extremly light frames in steel...reputedly his top-of-the-range weighs in at 0.9 kg
Norris Lockley apologies to Dale for the last paragraph..Settle UK