Slitherine

i was looking though an old copy of wrg rule pulbished in the 80s and wondered why do the fog-a rules not say anything about special formations eg the wedge or cantabrian circle

In Fog it's assumed that BGs are fighting in their appropriate formations, these are not modelled on the table.

Except that cavalry in a single rank may be assumed to represent some sort of skirmishing+shooting oriented formation, e.g. if light spear armed "cantabrian circle" or if bow armed "african" in old WRG terms.