Because of the Bibliotheca Alexandrina's unique position & global importance, materials will not generally be weeded from its collections. Exceptions to this are multiple copies of items and old or outdated reference materials. Multiple copies of little used titles in the general collection (as reflected in usage statistics) will be withdrawn. Old and outdated reference materials will be retained for their historical and research value, but will be moved to the general collection or one of the special collections, in order to maintain the currency and integrity of the reference collection.