When you mention "OCB Squadron" what does the OCB stand for?

Officer Commanding “B” Squadron, in the case of what you asked that would be Major I.B. “Ibby” Aird Who was leading that Squadron.
A typical WWII British Tank Squadron would break down as such:
Armoured/Tank Squadrons used Shermans, Cromwells or Churchills.5 troops to a squadron each troop has 3 tanks later reorganized to 4 troops each of 4 tanks,Squadron HQ had 4 tanks.
The Yeomanry Officer Commanding Squadron ‘B’ (in early Normandy Invasion tactics) would hold back his Squadron and reconnoiter the situation at hand. I’ve heard rumors that Michael Wittmann’s actions that day was 50% of  the decision as to why the numbers of tanks in a Squadron were up-gunned. To put it lightly, Monty’s blundering at Caen did a lot of damage to the plans. Not to mention putting his men into the worst situation. Personally speaking I say he was unsound tactically for the Normandy Campaign.