It's not used in aviation to the best of my knowledge but there exists a range of two letter codes which are used by 'serious' radio operators. 'CC' is 'Roger' or 'Wilco'. Others are 'DE' - 'this is' and the well known 'CQ' which is 'Hello'.
Perhaps a Radio Ham or someone with a better memory could help. These terms are also used by people who need to log spoken RT, as shorthand.
I agree it's use as spoken voice procedure is wrong but it is at least based on something. Probably old ex mil folk are the main culprits, I've heard it a few times.
Quaint
