Glossary

Definitions of the standards and domain terms used throughout this documentation.

Standards

TZ Database: The community-maintained database of named time zones (e.g. Europe/Berlin), also known as the IANA time-zone database or tz. Modelled by Chronology.
Unix time: A point in time expressed as the number of seconds since the Unix epoch (1 January 1970 UTC). Modelled by Chronology.
DOS date/time: A packed date-and-time representation as used by the MS-DOS file system, covering the years 1980–2107. Modelled by Chronology.
ITU-T E.164: The ITU-T recommendation defining the international public telecommunication numbering plan — the structure of international telephone numbers. Modelled by Communication.
RFC 4180: The specification of the common format and MIME type for Comma-Separated Values (CSV) files. Implemented by File.CSV.
ISO 3166-1: Codes for the representation of names of countries — Part 1: Country code. Modelled by Geography.
ISO 3166-2: Codes for the representation of names of countries and their subdivisions — Part 2: Country subdivision code. Modelled by Geography.
UN M49: The United Nations Standard Country or Area Codes for Statistical Use (Series M, No. 49), assigning numeric codes to countries, areas, and regions. Modelled by Geography.
ISO 639: Codes for the representation of names of languages, published in several parts. Modelled by Language.
ISO 639 Part 1: The alpha-2 (two-letter) language code, e.g. en for English.
ISO 639 Part 2: The alpha-3 (three-letter) language code, published as a terminology (T) code and a bibliographic (B) code.
ISO 639 Part 3: An alpha-3 code providing comprehensive coverage of languages, extending beyond the major languages covered by Parts 1 and 2.
ISO 639 Part 5: An alpha-3 code for language families and groups.
ISO 15924: Codes for the representation of names of scripts (writing systems), e.g. Hans for Simplified Chinese script. Modelled by Language.
BCP 47: Best Current Practice 47, the IETF specification for language tags (as defined by RFC 5646), used to identify languages in a hyphen-separated sequence of subtags. Modelled by LanguageTag.
ISO 4217: Codes for the representation of currencies and funds — current currency and funds codes (Tables A.1–A.2) and historic denominations (Table A.3). Modelled by Money.

Domain terms

Money type: A value type that combines an amount with an ISO 4217 currency code, after Martin Fowler’s Patterns of Enterprise Application Architecture. See The Money type.
Subtag: One hyphen-delimited part of a BCP 47 language tag — for example the primary language, script, or region — each occupying a fixed position and carrying a distinct meaning. See Anatomy of a language tag.
Code list: The full set of codes defined by a standard (for example, every ISO 4217 currency or ISO 3166-1 country), together with their numeric codes and names. The Reference section publishes these as generated tables.
Strongly-typed code: A code from a standard represented as a distinct .NET type — an enum where the codes map cleanly onto one, or a struct-based IStringEnum where they don’t — so that invalid values are caught at compile time rather than at runtime. See Strongly-typed codes.