The USMS is authorized to provide for the maintenance and housing of protected witnesses whenever they appear for trial, pre-trial conferences, or return to a danger area for other appearances approved by OEO. The USMS is authorized to pay for the costs of travel and other associated maintenance expenses. Attorneys should not prepare "Fact Witness Certificates," and Fact Witness fees and allowances should not be disbursed to protected witnesses who are under the protection and maintenance of the USMS. (Witnesses who voluntarily withdraw from participation in the Witness Security Program are exempt from this restriction.)