OS GB British Grid coordinates

Add British OS GB grid reference system to the conversions please. The datum and grid numbers differ from MGRS and it would be very handy for anyone working between both systems (survey work in particular frequently uses both as well as Lat Lon, and there is nothing available currently that does all three).
Other users would simply have an additional conversion field that they could reorder to the bottom of it is irrelevant to them)
Thanks for considering