When deleting a field from the Registration Form the admin has the option to remove it from that group (choosing the Remove button) so the field. As a result, data related to this field will be available for use by other managers under Community Fields.
By clicking the Delete Field Permanently option, Community Managers can remove a field permanently from the community. To do that an admin will use the Delete Field Permanently option.
Note: Once the field has been deleted permanently, the field’s data can not be restored.
To delete a field from the Registration Form:
-Go into the group and choose Settings (the gear icon)
-Choose Registration Form
-Choose the field to be deleted
-(Per the description above) Choose whether to Remove or Delete Field Permanently
-Click Confirm to delete the field
The field is now deleted from this group's form.