So I bought a reel each of BF862-235 and BF862-215. Other parts seem to have the same suffixes, but a quick web search comes up with nothing useful, and the datasheet links for the two types of parts go straight to the same place.
I'd guess this has something to do with ROHS/halogen free/greenie-knotted-knickers-of-the-month, but don't know for sure.
Wisdom?
Thanks
Phil Hobbs