So I understand there 's a physical difference. What I would like to understand is what to use when. I see both being advised
Yes, the pinout is different.
In the same link, it says when to use, which…
ah yes, i didn’t look at it that good. sorry for that.
It may be a cause of why sometimes it’s not possible to connect the batteries to the Cerbo, because not all vendors are provided in this list. Then it’s just trial and error to get the right cable i guess.
I use Victron can bms cable type a .. type b didn’t work…jk bms v19
Next week I will (try) to connect the second battery to the first 
Sorry my bad for mixing this up. I use type B indeed for JK inverter BMS and edited my post above to state it correctly. Some other BMS’s have their CAN L and CAN H on another pin and thus then need BMS Can A cable see link above for the pinouts of those cables..
Try out is the last resort when manuals are not clear… Most BMS’s it’s well written in the manuals. This year I find that JK inverter BMS updated their manuals in carton even with the BMS. Very nice clear manual.