Codes are as follows
Rwy State Group
8 figure
First 2 digits - rwy desig
Third - rwy depsoits
Fourth - extent of contamination (%)
Fifth and sixth - depth of contam
Seventh and eighth - braking action
Turbulence - beginning 5
6 figure
Second - degree of turb
Third to fifth - base of turb in 100s of feet
Sixth - thickness of turb layer in 1000s feet
Icing - beginning 6
Second - degree of icing
Third to fifth - base of icing in 100s of feet
Sixth - thickness of icing layer in 1000s feet
For all the extra codes, get hold of a Royal Air Force Flight Information Handbook (yellow book). I'm sure you must know somebody who knows somebody!!!!