Naming of source bands

Hi there,
can you help me understand the naming rationale of SAR satellite product source bands?
I am looking into calibration and want to find an automated way of parameterizing the node. I currently want to process an ASAR IMP product and when I leave the field sourceBands empty, the workflow finishes without error but no file is written (a bug imho).
Sometimes the bands just called Amplitude and Intensity, sometimes Amplitude_VV and Intensity_VV. I first thought the polarization is only appended when there are multiple polarizations but this is e.g. not the case for ASAR IMS products. So I thought the polarization might be appended when there are either multiple polarizations or real and imaginary bands in complex products. But in an ERS-1 IMS product it is again just called Intensity (next to the i and q bands).
So I am not seeing any pattern here. Is there one?
Best,
John