Ivy,

KAotW: The King's Army of the West (the original splitters [Hopton's & Lunsfords IIRC]:-)
KA: The King's Army - More splitters left the Knot !
RA: The Roundhead Association - The original opposition to the Brig's Edgehill Garden Party
These two (KA & RA) incorporated to form the ECWS.

AndyG