How to add custom member fields
As admin you can add custom member fields (text, number or date) in the group settings. For example player position, shirt number etc. These will show in the Excel member import when you add members as well as be included in the member export. These fields can be set to visible to all members of the group, visible for admins and member self (including the member’s guardians) or only for admins.
The administrator of the group can chose who has permission to edit this field, read more about that here.