(from Collection Development Guidelines, Part V. General Collection Policies, C. Acquisition Procedures Affecting Collection Policies, No. 9):

Gifts: Gifts of library materials are accepted with the understanding that there are no conditions attached to their disposition. Only those materials in good physical condition and which conform to the library's collection criteria will be added. Generally, only items published within the past five years will be considered for addition. Periodicals are not normally accepted. No estimation of value will be provided for any gift, but a letter of acknowledgement will be provided if requested. Unneeded items will disposed of by sale, exchange, donation or discard.