This article needs to be updated. The reason given is: The standard is now known as ISO/IEC 14651:2020 (the sixth edition of the standard). Please help update this article to reflect recent events or newly available information. Last update: September 2018(July 2021)
ISO/IEC 14651:2016, Information technology -- International string ordering and comparison -- Method for comparing character strings and description of the common template tailorable ordering, is an International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC) standard specifying an algorithm that can be used when comparing two strings. This comparison can be used when collating a set of strings. The standard also specifies a datafile specifying the comparison order, the Common Tailorable Template, CTT. The comparison order is supposed to be tailored for different languages (hence the CTT is regarded as a template and not a default, though the empty tailoring, not changing any weighting, is appropriate in many cases), since different languages have incompatible ordering requirements. One such tailoring is European ordering rules (EOR), which in turn is supposed to be tailored for different European languages.
The Common Tailorable Template (CTT) data file of this ISO/IEC standard is aligned with the Default Unicode Collation Entity Table (DUCET) datafile of the Unicode collation algorithm (UCA) specified in Unicode Technical Standard #10.
This is the fourth edition of the standard and was published on 2016-02-15, corrected on 2016-05-01 and covers up to and including Unicode 8.0. One additional amendment Amd.1:2017 was published in September 2017 and covers up to and including Unicode 9.0.
Collation is the assembly of written information into a standard order. Many systems of collation are based on numerical order or alphabetical order, or extensions and combinations thereof. Collation is a fundamental element of most office filing systems, library catalogs, and reference books.
Extended Binary Coded Decimal Interchange Code is an eight-bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems. It descended from the code used with punched cards and the corresponding six-bit binary-coded decimal code used with most of IBM's computer peripherals of the late 1950s and early 1960s. It is supported by various non-IBM platforms, such as Fujitsu-Siemens' BS2000/OSD, OS-IV, MSP, and MSP-EX, the SDS Sigma series, Unisys VS/9, Unisys MCP and ICL VME.
ISO/IEC 8859-1:1998, Information technology — 8-bit single-byte coded graphic character sets — Part 1: Latin alphabet No. 1, is part of the ISO/IEC 8859 series of ASCII-based standard character encodings, first edition published in 1987. ISO/IEC 8859-1 encodes what it refers to as "Latin alphabet no. 1", consisting of 191 characters from the Latin script. This character-encoding scheme is used throughout the Americas, Western Europe, Oceania, and much of Africa. It is the basis for some popular 8-bit character sets and the first two blocks of characters in Unicode.
A regular expression, sometimes referred to as rational expression, is a sequence of characters that specifies a match pattern in text. Usually such patterns are used by string-searching algorithms for "find" or "find and replace" operations on strings, or for input validation. Regular expression techniques are developed in theoretical computer science and formal language theory.
Unicode, formally The Unicode Standard, is a text encoding standard maintained by the Unicode Consortium designed to support the use of text written in all of the world's major writing systems. Version 15.1 of the standard defines 149813 characters and 161 scripts used in various ordinary, literary, academic, and technical contexts.
UTF-8 is a variable-length character encoding standard used for electronic communication. Defined by the Unicode Standard, the name is derived from Unicode Transformation Format – 8-bit.
UTF-16 (16-bit Unicode Transformation Format) is a character encoding capable of encoding all 1,112,064 valid code points of Unicode (in fact this number of code points is dictated by the design of UTF-16). The encoding is variable-length, as code points are encoded with one or two 16-bit code units. UTF-16 arose from an earlier obsolete fixed-width 16-bit encoding, now known as UCS-2 (for 2-byte Universal Character Set), once it became clear that more than 216 (65,536) code points were needed.
C++ is a high-level, general-purpose programming language created by Danish computer scientist Bjarne Stroustrup. First released in 1985 as an extension of the C programming language, it has since expanded significantly over time; as of 1997 C++ has object-oriented, generic, and functional features, in addition to facilities for low-level memory manipulation. It is almost always implemented as a compiled language, and many vendors provide C++ compilers, including the Free Software Foundation, LLVM, Microsoft, Intel, Embarcadero, Oracle, and IBM.
In the C++ programming language, the C++ Standard Library is a collection of classes and functions, which are written in the core language and part of the C++ ISO Standard itself.
Alphabetical order is a system whereby character strings are placed in order based on the position of the characters in the conventional ordering of an alphabet. It is one of the methods of collation. In mathematics, a lexicographical order is the generalization of the alphabetical order to other data types, such as sequences of numbers or other ordered mathematical objects.
The European ordering rules, define an ordering for strings written in languages that are written with the Latin, Greek and Cyrillic alphabets. The standard covers languages used by the European Union, the European Free Trade Association, and parts of the former Soviet Union. It is a tailoring of the Common Tailorable Template of ISO/IEC 14651. EOR can in turn be tailored for different (European) languages. But in inter-European contexts, EOR can be used without further tailoring.
The Unicode collation algorithm (UCA) is an algorithm defined in Unicode Technical Report #10, which is a customizable method to produce binary keys from strings representing text in any writing system and language that can be represented with Unicode. These keys can then be efficiently byte-by-byte compared in order to collate or sort them according to the rules of the language, with options for ignoring case, accents, etc.
T.61 is an ITU-T Recommendation for a Teletex character set. T.61 predated Unicode, and was the primary character set in ASN.1 used in early versions of X.500 and X.509 for encoding strings containing characters used in Western European languages. It is also used by older versions of LDAP. While T.61 continues to be supported in modern versions of X.500 and X.509, it has been deprecated in favor of Unicode. It is also called Code page 1036, CP1036, or IBM 01036.
The C0 and C1 control code or control character sets define control codes for use in text by computer systems that use ASCII and derivatives of ASCII. The codes represent additional information about the text, such as the position of a cursor, an instruction to start a new line, or a message that the text has been received.
sort is a generic function in the C++ Standard Library for doing comparison sorting. The function originated in the Standard Template Library (STL).
Unicode equivalence is the specification by the Unicode character encoding standard that some sequences of code points represent essentially the same character. This feature was introduced in the standard to allow compatibility with preexisting standard character sets, which often included similar or identical characters.
Many Unicode characters are used to control the interpretation or display of text, but these characters themselves have no visual or spatial representation. For example, the null character is used in C-programming application environments to indicate the end of a string of characters. In this way, these programs only require a single starting memory address for a string, since the string ends once the program reads the null character.
The Universal Coded Character Set is a standard set of characters defined by the international standard ISO/IEC 10646, Information technology — Universal Coded Character Set (UCS), which is the basis of many character encodings, improving as characters from previously unrepresented typing systems are added.
Runic is a Unicode block containing runic characters. It was introduced in Unicode 3.0 (1999), with eight additional characters introduced in Unicode 7.0 (2014). The original encoding of runes in UCS was based on the recommendations of the "ISO Runes Project" submitted in 1997.
ISO/IEC JTC 1/SC 2 Coded character sets is a standardization subcommittee of the Joint Technical Committee ISO/IEC JTC 1 of the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC), that develops and facilitates standards within the field of coded character sets. The international secretariat of ISO/IEC JTC 1/SC 2 is the Japanese Industrial Standards Committee (JISC), located in Japan. SC 2 is responsible for the development of the Universal Coded Character Set standard, which is the international standard corresponding to the Unicode Standard.
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
