Section 25.1543 - Instrument markings: generalFor each instrument-
(a) When markings are on the cover glass of the instrument, there must be means to maintain the correct alignment of the glass cover with the face of the dial; and(b) Each instrument marking must be clearly visible to the appropriate crewmember.Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25-72, 55 FR 29786, July 20, 1990