Letter Designator After Callsign

[MG64]

Could someone explain what the designated letter D stands for after your call sign? When I change from DMR on the Openspot 2 and use the connectors tab to switch to DStar to my home reflector it show the letter D after my call sign. I even unplugged the Openspot 2 and rebooted and its still there. Thanks

[HA2NON]

Can you please post a screenshot about it?