The standard is intended to include widely used ferrite core families, especially for electronic applications. However, even if there are very similar sizes, e.g. E24/25 (USA) and E24,5 (metric), they are included separately due to their high popularity and definition in national standards.
On the other hand, a type of core produced by only one or two manufacturers would not be included.
Apart from the multi-part IEC 62317 standard itself there are other documents which are pertinent. These would be for instance:
As of October 2013, some of these standards were not published yet, and other standards are applicable: