do you mean grid ref's?
i.e. BE16
or AM27 etc?
if you hit F5 you will see that your map charts are devided into areas marked by letters AM, AN, AL etc.
each of these is devided into rectangles marked 01 to 99
so if you're told to patrol AL36 simply find AL on your map (marked in bold letters) and zoom in until you find grid 36. this is your patrol zone!
Good Hunting Heir Kaleun!