1.1 This specification specifies shape, size, spacing, and shading of letters and numerals to be used aboard ship.

1.2 Characters are of Five Types:

1.2.1 Type 1—Plain letters and numerals (16 units).

1.2.2 Type 2—Block letters and numerals (12 units).

1.2.3 Type 3—Type 2 characters with shading (shading—1 unit).

1.2.4 Type 4—Block letters (10 units) and numerals (12 units).

1.2.5 Type 5—Type 4 characters with shading (shading—1 unit).

1.3 This specification does not give location or size of various shipboard markings incorporating letters and numerals.