The ISO 10110 standards are widely used in Europe, so it is relevant to cover here. With regards to this chapter, part 7 of ISO 10110 deserves attention. The ISO 14997:2011 standard establishes the physical principles and practical means for implementating the methods, as specified in ISO 10110-7 for measuring surface imperfections. The treatment here includes references, where needed, to the appropriate standard. The introduction of ISO 10110-7 reads thusly:
Measurement is only required as a second stage operation following inspection necessary to determine location and to select a surface imperfection worthy of study, see ISO 14997. In such cases, a drawing notation indicating this level of inspection is required and can be added to the specification. This process, not depending on the eye, is more time consuming and is usually only carried out when a surface imperfection could influence performance as, for example, in laser or low-light level systems or when a more precise measure is demanded.
This is an important paragraph that establishes the visual inspection as the first stage and the measurement inspection as the second stage. Do not forget it!
ISO 10110-7 refers to a localized surface imperfection by its square root area in millimeters and to long scratches (longer than 2 mm) by their width in millimeters. However, unlike the scratch and dig designations in the milspecs, the ISO refers to these imperfections in terms of localized surface imperfections, long scratches, and edge chips, as well. This standard applies to transmitting and reflecting coated and uncoated surfaces of finished optical elements and to optical assemblies.
The drawing indication for the number and size of surface imperfections permissible within the effective aperture of a surface is

and for localized surface imperfections in optical assemblies,

where 5 is the code for surface imperfections, 15 is the code for localized surface imperfections in optical assemblies, N is the number of allowed imperfections of the maximum permitted size, and A is a grade number that equals the square root of the area of the maximum allowed imperfection (in millimeters).

If needed, coating blemishes may be specified separately from the localized surface imperfections. Following the indication for surface imperfections and separated from it by a semicolon, the indication for coating blemishes permissible within the effective aperture of a surface or assembly is

coating blemishes permissible where C is the designation for coating blemishes, N0 is the number of allowed blemishes of the maximum permitted size, and A0 is the grade number defined for general indication. Therefore, the designation for the imperfection indication including coating blemishes for surfaces is

and for assemblies the designation is

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If the only existing designation is

then the coating blemishes should be included in the permissible surface imperfection indication.
Long scratches are those that are longer than 2 mm; their designation is

where L is the indication for long scratches, N00 is the number of allowed long scratches, and A00 specifies the maximum allowed width of the scratches (in millimeters). The imperfection indication including coating blemishes and long scratches is

If the only existing designation is

then the long scratches or coating blemishes should be included in the permissible surface imperfection indication.
The designation of edge chips is

where E is the edge-chip designation, and A000 is the maximum permitted chip in millmeters. If the indication for edge chips is not given, then edge chips are allowed so long as they do not enter the optical effective aperture.

The complete imperfection indication for all of the imperfections mentioned here is

where 5 represents the surface imperfections, 15 represents the surface imperfections in optical assemblies, N x A is the indication for surface imperfections, CN’ A‘ is the indication for coating blemishes, L/N’’ A’’ is the indication for long scratches, and EA‘’‘ is the indication for edge chips.
It appears that short scratches, less so than ones longer than 2 mm, which are indicated by L, are indicated by 5/N x A for the surface, 15/N x A for assemblies, and C/N’ x A’ for coatings. These short scratches—along with other localized imperfections (pits, sleeks, scuffs, fixture marks, or coating blemishes)—are calculated as the square root of the area of the maximum allowed imperfection, expressed in millimeters. The parameter comparable with the localized surface imperfection in ISO 10110-7 is the dig of the milspecs.