(B)
Either of the following inscriptions shall be clearly visible on three sides of such mobile office in letters not less than three inches high:
“UNITED STATES GOVERNMENT VEHICLE
“FOR OFFICIAL USE ONLY”;
Or
“MOBILE OFFICE OF SENATOR XXXXX
“FOR OFFICIAL USE ONLY”.
The Committee on Rules and Administration of the Senate may prescribe regulations to waive or modify the requirement under subparagraph (B) if such waiver or modification is necessary to provide for the public safety of a Senator and the Senator’s staff and constituents.