Some properties and vocabularies are internally defined in openBIS.
These can be identified by the $ sign.
Internal properties (e.g. $NAME, $BARCODE, etc) cannot be deleted nor modified, not even by an instance admin.
Internal vocabularies (e.g. $DEFAULT_COLLECTION_VIEWS, etc), cannot be deleted and their existing terms cannot be deleted nor modified, however an instance admin can add new terms to an internal vocabulary.