Use the Add Custom Field button to add new fields. Choose a name, type (numeric, text etc.), and configure preferences for the field you’re adding.
Custom fields for items can be associated to groups. For example, your Camera Lens group can have a custom field ‘Focal Length’, which will only appear with camera lenses.
Deleting a custom field also deletes all the associated values. Say your Camera Lens have a custom field ‘Focal Length’. Deleting Focal Length will remove this custom field from all lenses, and also delete all recorded values. This action cannot be undone.