Additional Considerations

Members in the Member Data Provider that don't need to be in DutyMan

Typically these are members who are not required to do duties. You want to keep them in your membership system but there is no need for them in DutyMan.

The way to do this is to omit them from your CSV file when you synchronise DutyMan. Your Membership Data Provider (MDP) should have the ability to define custom member fields. Set up one to indicate whether the member is or is not required to do duties. If your MDP has the ability to produce a subset of members then you can select only those required to do duties before downloading. Otherwise you can make the selection in your spreadsheet program and filter out those who are not needed in DutyMan.

Members in DutyMan but not in the Member Data Provider

It is not unusual for there to be entities, such as other clubs or guest race team members, who need to be in DutyMan but should not be listed as members in your membership system.

Just add them to your list of members in DutyMan via >Members >List. Because they will not have Member DBIDs they will not be affected by synchronisation.