RFC 3454 (rfc3454) - Page 1 of 91


Preparation of Internationalized Strings ("stringprep")



Alternative Format: Original Text Document



Network Working Group                                         P. Hoffman
Request for Comments: 3454                                    IMC & VPNC
Category: Standards Track                                    M. Blanchet
                                                                Viagenie
                                                           December 2002


        Preparation of Internationalized Strings ("stringprep")

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2002).  All Rights Reserved.

Abstract

   This document describes a framework for preparing Unicode text
   strings in order to increase the likelihood that string input and
   string comparison work in ways that make sense for typical users
   throughout the world.  The stringprep protocol is useful for protocol
   identifier values, company and personal names, internationalized
   domain names, and other text strings.

   This document does not specify how protocols should prepare text
   strings.  Protocols must create profiles of stringprep in order to
   fully specify the processing options.

Table of Contents

   1. Introduction....................................................3
     1.1 Terminology..................................................4
     1.2 Using stringprep in protocols................................4
   2. Preparation Overview............................................6
   3. Mapping.........................................................7
     3.1 Commonly mapped to nothing...................................7
     3.2 Case folding.................................................8
   4. Normalization...................................................9
   5. Prohibited Output..............................................10
     5.1 Space characters............................................11
     5.2 Control characters..........................................11
     5.3 Private use.................................................12



Hoffman & Blanchet          Standards Track