Shoe size "Footwear - Sizing - Vocabulary and terminology"; currently in development are companion standards ISO/TS 19409 "Footwear - Sizing - Measurement of last dimensions" and ISO/TS 19410 "Footwear - Sizing - Inshoe measurement". The adult shoe sizes are calculated from typical last length, which is converted from foot length in mm by adding an allowance of two shoe sizes: where formula_13 is foot length in mm. Direct conversion between adult UK, European and Mondopoint shoe size systems is derived as follows: Exact foot lengths may contain repeating decimals because the formulas include division by 3; in practice, approximate interval steps of
ISO 639 macrolanguage not forming a macrolanguage despite forming a mutually intelligible dialect continuum. Even all dialects of Hindi are considered as separate languages. Basically, ISO 639-2 and ISO 639-3 use different criteria for dividing language varieties into languages, 639-2 uses shared writing systems and literature more whereas 639-3 focuses on mutual intelligibility and shared lexicon. The macrolanguages exist within the ISO 639-3 code set to make mapping between the two sets easier. There are fifty-six language codes in ISO 639-2 that are considered to be macrolanguages in ISO 639-3. The use of this category of macrolanguage was applied in "Ethnologue", starting in