Hi Andrew, ..”C” rate is generally simply a ration of the manufacturers recommended continuous discharge amps compared to the stated cell capacity in Ah.
Also, it is not uncommon to see more than one one “C” rate on a battery... Continuous, Max, or even 30 sec or 10 sec “ Burst” C rate. That is common on RC Lipo packs.
...where did you hear the term CDR used ? ...... it is not common