16 Va. Admin. Code § 25-50-190
A. Any boiler or pressure vessel having been inspected and declared unsafe by the chief inspector or commonwealth inspector shall be stamped by the inspector with the letters "XXX" on both sides of the postal abbreviation of this Commonwealth, as shown by the following facsimile, which will designate a condemned boiler or pressure vessel:
XXX VA XXX
§ 40.1-51.6 of the Code of Virginia.
Derived from VR425-01-75 § 2.18, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993; Virginia Register Volume 15, Issue 5, eff. January 1, 1999.