25 CFR 700.531 - Government property.
Employees shall be held accountable for Government property and monies entrusted to their individual use or in connection with their official duties. An employee has a positive duty to protect and conserve Government property and to use it economically and for official purposes only, for example:
(a) Only official documents and materials may be reproduced on Government reproduction equipment.
(b) Government vehicles may be used only on official business and may not be used for personal use or for travel to or from an employee's place of residence, unless specifically authorized or assigned by the supervisor.
(c) An employee may not use FTS to make personal phone calls at Government expense.
(d) An employee may not use Government purchase authority for personal acquisitions even though reimbursement is made.