No CAL is the job the majority of us do, its basically provides be it to the customer or just in the cab work (green boxes at side road). Youll do faults and repairs too.
I forget what it stands for I know OMI stands for One Man Install.
You'll get UG training later and that comes with a pay rise around 3 k the FVR guys I believe have to do the internal course to get the same pay rise.
From what Ive seen I would rather do the internal course for an extra 3 k than the you UG far less taxing.
My comments are my own and represent my opinion only not that of any person or company I may have links to.