Custom fields
A custom field can be mandatory or not. If you set it to mandatory, you also need to define a default value. The default value will be automatically added to new user or subscription records, as well as to existing records without a value in the custom field. For existing records that already have a value in the custom field, this information will not be overwritten. You cannot manually add new users or subscriptions unless there is a value in all mandatory custom fields.
For more information on managing custom fields, see Manage custom fields.