It's great to see a concrete proposal for frequency of updates (i.e how to use dct:accrualPerdiodicity/dct:Frequency), i.e. the vocabulary of frequencies. But in the corresponding SKOS file, the frequencies are only typed as SKOS concepts, not as dct:Frequency. Actually I don't really bother, but I know some people will notice and may be reluctant to use these resources.
This issue has been reported by Antoine Isaac:
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