x1 is measured in x2 (number, default 1) bits/shannons (unit of data/information) of logarithmic base x3 (default 2)
See skami, datni, bitnymei, baitni // Decimal prefixed forms (powers of 1000): ki'orbitni megbitni gigbitni tetybitni petybitni xexybitni zepybitni gotybitni // Binary prefixed forms (powers of 1024): kirbibitni merbibitni girbibitni terbibitni perbibitni xerbibitni zerbibitni gorbibitni // x3 is for defining units with bases other than 2, e.g. trits (bitnrci), nats (bitnrte'o), dits/bans/hartleys (bitnrdau)