Huawei Nova CAN -Lxx? I am asked to buy the Huawei Nova CAN-L12...it has to be above CAN-L12C635B140......

But merchants of the Huawei Nova do not specify if it is CAN-L12, or L02, or L(other)..What is the CAN-xxxx coding? -> is it a software version that I don't really have to worry about and can be achieved through updates?

Thank you for your help!
The sub-model (CAN-Lxx) indicates the network band it supports and therefore the region it best suits. A specs listing of CAN-L02 can be seen on PDAdb (you could search for other sub-models, too - just search "Huawei Nova CAN").

Inspect the "Supported Cellular Network" section and see how it matches up to your local carrier. It's unlikely that you won't be able to use the phone at all if you buy the wrong model (that doesn't match), but it's likely you'll lose LTE support if you do - all you get will be GSM/WCDMA/HSDPA.

The long trailing digits are the software revision for this particular sub-model, and can be updated to the latest one once you get your hands on the device.