:SDNFSTATUS is used to give you a view of the current status of the element. It has 4 different settings: AVEVA E3D™ to signify the item originated in Model; ADDED indicates that the item has been added to the model externally, by Merging;
CHANGED means that the item has been modified externally; and
DELETED means that the item was in the original Design model but has not returned from the external model. The last case may occur for one of several reasons. The item may not have been exported in the first place; it may have been added after the model was exported or it was deleted by the external system for some reason.
!!sndfvisibleudas( |SDNF|, false, |SDNFEMARK| ), this would hide all SDNF UDAs except :SDNFEMARK.