Internet Assigned Numbers Authority

                                                Collation Registry for Internet Application Protocols

   Last Updated
           2013-08-20

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   Description

 [RFC4790] creates an abstraction framework so that application protocols
 can precisely identify a comparison function and the repertoire of comparison
 functions can be extended in the future. This document defines an IANA-maintained
 registry of collations for comparing, searching and sorting international strings.

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       Collation                                                         Description                                                      Reference
                     The "i;ascii-numeric" collation is a simple collation intended for use with arbitrary sized unsigned decimal integer
    i;ascii-numeric  numbers stored as octet strings. US-ASCII digits (0x30 to 0x39) represent digits of the numbers. Before converting   [RFC4790]
                     from string to integer, the input string is truncated at the first non-digit character. All input is valid; strings
                     which do not start with a digit represent positive infinity.
                     The "i;ascii-casemap" collation is a simple collation which operates on octet strings and treats US-ASCII letters
    i;ascii-casemap  case-insensitively. It provides equality, substring and ordering operations. All input is valid. Note that letters   [RFC4790]
                     outside ASCII are not treated case- insensitively.
                     The "i;octet" collation is a simple and fast collation intended for use on binary octet strings rather than on
        i;octet      character data. Protocols that want to make this collation available have to do so by explicitly allowing it. If not [RFC4790]
                     explicitly allowed, it MUST NOT be used. It never returns an "undefined" result. It provides equality, substring and
                     ordering operations.
                     The "i;unicode-casemap" collation is a simple collation which is case-insensitive in its treatment of characters. It
                     provides equality, substring, and ordering operations. The validity test operation returns "valid" for any input.
   i;unicode-casemap                                                                                                                      [RFC5051]
                     This collation allows strings in arbitrary (and mixed) character sets, as long as the character set for each string
                     is identified and it is possible to convert the string to Unicode. Strings which have an unidentified character set
                     and/or cannot be converted to Unicode are not rejected, but are treated as binary.

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