Mapping Characters for Classes of the Preparation, Enforcement, and Comparison of Internationalized Strings (PRECIS)
RFC 7790
| Document | Type | RFC - Informational (February 2016; No errata) | |
|---|---|---|---|
| Authors | Yoshiro Yoneya , Takahiro Nemoto | ||
| Last updated | 2016-02-29 | ||
| Replaces | draft-yoneya-precis-mappings | ||
| Stream | IETF | ||
| Formats | plain text html pdf htmlized bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Peter Saint-Andre | ||
| Shepherd write-up | Show (last changed 2015-07-20) | ||
| IESG | IESG state | RFC 7790 (Informational) | |
| Action Holders |
(None)
|
||
| Consensus Boilerplate | Yes | ||
| Telechat date | |||
| Responsible AD | Barry Leiba | ||
| Send notices to | (None) | ||
| IANA | IANA review state | Version Changed - Review Needed | |
| IANA action state | No IANA Actions | ||
Internet Engineering Task Force (IETF) Y. Yoneya
Request for Comments: 7790 JPRS
Category: Informational T. Nemoto
ISSN: 2070-1721 Keio University
February 2016
Mapping Characters for Classes of the Preparation, Enforcement, and
Comparison of Internationalized Strings (PRECIS)
Abstract
The framework for the preparation, enforcement, and comparison of
internationalized strings (PRECIS) defines several classes of strings
for use in application protocols. Because many protocols perform
case-sensitive or case-insensitive string comparison, it is necessary
to define methods for case mapping. In addition, both the
Internationalized Domain Names in Applications (IDNA) and the PRECIS
problem statement describe mappings for internationalized strings
that are not limited to case, but include width mapping and mapping
of delimiters and other special characters that can be taken into
consideration. This document provides guidelines for designers of
PRECIS profiles and describes several mappings that can be applied
between receiving user input and passing permitted code points to
internationalized protocols. In particular, this document describes
both locale-dependent and context-depending case mappings as well as
additional mappings for delimiters and special characters.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Not all documents
approved by the IESG are a candidate for any level of Internet
Standard; see Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7790.
Yoneya & Nemoto Informational [Page 1]
RFC 7790 PRECIS Mapping February 2016
Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Protocol-Dependent Mappings . . . . . . . . . . . . . . . . . 3
2.1. Delimiter Mapping . . . . . . . . . . . . . . . . . . . . 3
2.2. Special Mapping . . . . . . . . . . . . . . . . . . . . . 4
2.3. Local Case Mapping . . . . . . . . . . . . . . . . . . . 4
3. Order of Operations . . . . . . . . . . . . . . . . . . . . . 5
4. Security Considerations . . . . . . . . . . . . . . . . . . . 5
5. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.1. Normative References . . . . . . . . . . . . . . . . . . 6
5.2. Informative References . . . . . . . . . . . . . . . . . 6
Appendix A. Mapping Type List . . . . . . . . . . . . . . . . . 8
A.1. Mapping Type List for Each Protocol . . . . . . . . . . . 8
Appendix B. Why Local Case Mapping Is an Alternative to Case
Mapping in the PRECIS Framework . . . . . . . . . . 8
Appendix C. Limitations of Local Case Mapping . . . . . . . . . 9
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction
In many cases, user input of internationalized strings is generated
through the use of an input method editor ("IME") or through copy-
and-paste from free text. Users generally do not care about the case
and/or width of input characters because they consider those
characters to be functionally equivalent or visually identical.
Furthermore, users rarely switch the IME state to input special
characters such as protocol elements.
Yoneya & Nemoto Informational [Page 2]
RFC 7790 PRECIS Mapping February 2016
For Internationalized Domain Names (IDNs), the IDNA Mapping
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