I have an '06 GF HKEK. My question is about some info on the seattube. It has something like BS 6102:1 on the seattube. Does anyone know what this means?

It could also be 85 6102:1 it is hard to decide which because of the font used...

Originally, I thought it had something to do with the aluminum in the frame, but my wife's old('96) GF Wahoo has got the same code on it as well, but it is a CroMo frame

Any ideas?