This is not recommended, because it makes record management very complex for the collection. In some cases where isolated CZ bibs in the collection are of unacceptable quality, members may choose to unlink the CZ portfolio from the CZ bib and use an IZ/NZ bib record instead.  However, this can create significant complexities in keeping up with updates for that title.  If many CZ bib records in the collection are of unacceptable quality, it may be better to use IZ/NZ records for the entire collection.