history

[fred1]

what do the abbreviated letters stand for in events of the year

1909 P B T O by L
1959 M is L
1969 B C

[deliciou6]

what are the years talking about
i think bc means before christ or before common era, which are the same thing, but i have never seen a 1969 bc
it seems to be too far back unless your talking about ancient history
and i have no idea on the other two

[Brooksy]

1969 could be "British Concorde" ie when it first flew.