Diagnosis
V1 v2 is used by v3 v4, and therefore cannot be deleted.Deletion is only possible when the characteristic value is no longerused.

Procedure
If you want to delete &V1& &V2&, you must first change &V3& &V4& so thatV1 v2 is no longer used.
Note that further uses of &V1& &V2& may exist. That is, after you havechanged &V3& &V4&, the system may display yet another usage the nexttime you attempt the deletion. Hence, make sure you eliminate all usesof &V1& &V2&.