Oh, joy!

Few things delight the heart as much as finding an official Russian state standard of terms and definitions that provides equivalent terms in five languages—among them, just to be clear, English—only to find that a critical term given in the document does not occur in modern English (at least, as far as Google is concerned).

So I am left with no alternative than to cobble something together from the Russian definition of said term, which is a little awkward, but workable.

Cheers...