The meaning of some suffix code of FAG deep groove ball bearings

RSR-FAG Bearings which have one side with seal. Cases: 6207RSR.
ZR-FAG Bearings which have one side with shield. Cases: 6207ZR.
2ZR-FAG Bearings which have two-faced with seal. Cases: 62072ZR.
ZRN-FAG Bearings which have one side with shield ,and another side’s outer ring with snap ring groove. Cases: 6207ZRN.
2ZRN-FAG Bearings which have two-faced with shield, outer ring with snap ring groove. Cases: 62072ZRN.

The above suffix meaning is only for FAG bearings ,and different from other bearings.