dsb-ask
I understand, that in EPC Class-1 Generation-2 modulation methods no carrier is either added or supressed. Cause the digital baseband signal is non-zero in idle state, an idle carrier is transmitted in each of the 3 methods (which is obviously required for RFID with passive tags).
While DSB-ASK has a continuous carrier by definition, SSB-ASK and PR-ASK are effectively emitting a carrier due to the nature of the baseband signal.
I didn't exactly understand, what's the objective of your question. The significance of transmitting a carrier may be regarded different if it's related either to signal generation, spectral analysis or signal demodulation.
As a reference, I added EPC Class-1 Generation-2 spec. annex H, that gives a brief overview of involved modulation methods.