Making a Custom Attribute Editable or Uneditable
You can have a custom attribute that is fed directly into Salesforce B2C Commerce from a backend system-of-record.
You can set the externally-managed flag to indicate to Business Manager users that
they shouldn't edit these attribute directly. Such an attribute is considered externally
managed, because the attribute values are set in an external system. If the feed for an
uneditable attribute contains an incorrect value, you can fix the value by deselecting the
Externally Managed option and manually fixing it. When the value is fixed,
reselect the Externally Managed option.