Note: Using an IZ portfolio with a CZ bib is not recommended, as it results in less metadata control and the lack of portfolio updates. CZ portfolio, IZ/NZ bib advantages Maintenance efficiencies for large and frequently changing collections via automatically updated portfolios (e.g. URL updates) Aggregator collections: added and deleted titles managed automatically Selective collections: easy ordering and activation of new titles in active CZ collection Weekly list of CZ collection updates from ExLibris that can be used to update any outside systems, like OCLC holdings and A-Z lists. Generally better bibliographic metadata quality, particularly for records obtained from WorldCat. If linked to NZ, bib records with OCLC numbers are updated regularly. Bib records can be updated on-demand in WorldCat and exported to the IZ/NZ. CZ portfolio, IZ/NZ bib limitations CZ collections may be inconsistent with collections offered through content providers. Potential delays in adding new title portfolios to CZ collections Not all collections are present in the CZ. Titles removed from the CZ collection will leave behind empty bib records in the IZ/NZ. Updates to IZ-only records must either be scheduled to run automatically on a periodic basis or staff must run them manually to get data updates in place.