Note that in the English language, there is a rule in regard to forming compound nouns, which is that only the head of the compound can carry the plural marker.
So for instance, whereas the compound noun phrase "law school entrance exams" is perfectly fine, "law schools entrance exam" is not. It has a plural on "schools", where it is not allowed to be, because that is not the head of the noun phrase.
According to this rule, we should not have words like "data processing", unless we treat "data" as plural. If we treat "data" as the plural of "datum", we must make it "datum processing".
Is that how it is in British English, or do they still make it "data processing"?
In any case, one cannot be a proper pedant about "data" and "datum", while continuing to use terms like "data storage".
So for instance, whereas the compound noun phrase "law school entrance exams" is perfectly fine, "law schools entrance exam" is not. It has a plural on "schools", where it is not allowed to be, because that is not the head of the noun phrase.
According to this rule, we should not have words like "data processing", unless we treat "data" as plural. If we treat "data" as the plural of "datum", we must make it "datum processing".
Is that how it is in British English, or do they still make it "data processing"?
In any case, one cannot be a proper pedant about "data" and "datum", while continuing to use terms like "data storage".