International Organization for Standardization

Information technology - International string ordering and comparison - Method for comparing character strings and description of the common template tailorable ordering - Fourth Edition
 N ISO/IEC 14651

Annotation

This International Standard defines the following.

— A reference comparison method. This method is applicable to two character strings to determine their collating order in a sorted list. The method can be applied to strings containing characters from the full repertoire of ISO/IEC 10646. This method is also applicable to subsets of that repertoire, such as those of the different ISO/IEC 8-bit standard character sets, or any other character set, standardized or not, to produce ordering results valid (after tailoring) for a given set of languages for each script. This method uses collation tables derived either from the Common Template Table defined in this International Standard or from one of its tailorings. This method provides a reference format. The format is described using the Backus-Naur Form (BNF). This format is used to describe the Common Template Table. The format is used normatively within this International Standard.

— A Common Template Table. A given tailoring of the Common Template Table is used by the reference comparison method. The Common Template Table describes an order for all characters encoded in the Unicode 8.0 standard, included in ISO/IEC 10646:2014 and its Amendment 1. It allows for a specification of a fully deterministic ordering. This table enables the specification of a string ordering adapted to local ordering rules, without requiring an implementer to have knowledge of all the different scripts already encoded in the Universal Coded Character Set (UCS).

NOTE 1 This Common Template Table is to be modified to suit the needs of a local environment. The main worldwide benefit is that, for other scripts, often no modification is required and the order will remain as consistent as possible and predictable from an international point of view.