OC/CO/ which is which?

[ccw34]

Also discussed here:

OC or CO

Hi. Simple question. What is the difference militarily speaking between a Commanding Officer and a Officer Commanding. Is it referenced anywhere which we should use if the OC/CO of a Sqn. Cheers

and briefly here:

Put it on my (rank) tab!

I’m sure someone more knowledgeable than I will be along soon, but it was a mistake for it to be a called CO. A Commanding officer is someone at a certain OF rank, I think Brigadier? Possibly Colonel level?