When looking at the XC5 series of connectors from Omron, you may find some part numbers with the suffix “A”. The datasheet does not call out a meaning for this suffix.
Suffix “A” means that the connector comes with fastening pins. The fastening pins support the connector on a PCB securely. The fastening pin does not affect the mating connector. It is used to help hold the connector on the PCB and shouldn’t affect its performance.
For example, XC5B-4431-0 mates to XC5A-4482-1. At the same time, it also mates to XC5A-4482-1A.