In a relation file the phone number that has a black star in front (main phone number) is shown on top in the banner.
On the example below you see the data of the main contact (the contact with the filled star). If there is no main contact you will see the number with a black star here.
If a phone no longer exists (eg. when a client moves) you can delete it. Add another phone number and mark it as a favorite by clicking the black star in front. Then you can delete the old number via the recycle bin in front.
In the next release of AdminPulse, this trick will no longer be necessary: you simply will be able to delete the number with a black star.