Text in force at CS25-28: from CS25-0, effective 17 Oct 2003.
(See AMC 25.1543) For 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 crew member.
ED Decision 2003/002/RM · Source