Understand legend on double glazing glass

[Mungo]

Hi,
New double-glazing, and I'm trying to decypher the legend painted on
each pane
of glass.
At each corner there is
Darbytuf
Tempered
BS6206A
KM2070B (the letter B could be a 3)

Now I can make an intelligent guess at the first three lines, but what
is the
last line for?

Anyone help?

Thanks in advance

Mungo

[Weatherlawyer]

Post by Mungo
Hi,
New double-glazing, and I'm trying to decypher the legend painted on
each pane
of glass.
At each corner there is
Darbytuf

Darby toughened glass?

Post by Mungo
Tempered

Obvious. They dip each pane in a bucket of whale oil as they are
produced.

Post by Mungo
BS6206A
KM2070B (the letter B could be a 3)

British Standards Number 6206A-KM2070B