I had cause to check the terminals of an RF3 and as they were poorly marked, I thought it would be useful to document them here.
Looking at the photograph, below, the screw terminals in the top RH corner are A-wire, earth & B-wire (reading from top to bottom) and the IDCs in the bottom LH corner are B-wire, earth & A-wire (again reading from top to bottom).
At the same time, I decided to check the resistance of the common-mode chokes. Both were found to be 0.8 Ohm, when measured using my ex-Beattie Fluke 8022B DMM.