Shoe size characteristics of a system of shoe sizing to be known as Mondopoint" and ISO 3355:1975 "Shoe sizes - System of length grading (for use in the Mondopoint system)". ISO 9407:1991, "Shoe sizes—Mondopoint system of sizing and marking", is the current version of the standard. The Mondopoint system is based on average foot length and foot width for which the shoe is suitable, measured in millimetres. The length of the foot is measured as horizontal distance between the perpendiculars in contact with the end of the most prominent toe and the most prominent part of the heel. The width of the
ISO 639-1 (International Information Center for Terminology) is the registration authority for ISO 639-1 codes. New ISO 639-1 codes are not added if an ISO 639-2 code exists, so systems that use ISO 639-1 and 639-2 codes, with 639-1 codes preferred, do not have to change existing codes. If an ISO 639-2 code that covers a group of languages is used, it might be overridden for some specific languages by a new ISO 639-1 code. There is no specification on treatment of macrolanguages (see ISO 639-3). ISO 639-1 ISO 639-1:2002, "Codes for the representation of names of languages — Part 1: Alpha-2