Unified User-Agent String
draft-karcz-uuas-01

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Independent                                                     M. Karcz
Internet-Draft                                                UKLO Tczew
Updates: 7231 (if approved)                            November 10, 2014
Intended status: Experimental
Expires: May 14, 2015

                       Unified User-Agent String
                          draft-karcz-uuas-01

Abstract

   User-Agent is a HTTP request-header field. It contains information
   about the user agent originating the request, which is often used by
   servers to help identify the scope of reported interoperability
   problems, to work around or tailor responses to avoid particular user
   agent limitations, and for analytics regarding browser or operating
   system use. Over the years contents of this field got complicated
   and ambiguous. That was the reaction for sending altered version of
   websites to web browsers other than popular ones. During the
   development of the WWW, authors of the new web browsers used to
   construct User-Agent strings similar to Netscape's one. Nowadays
   contents of the User-Agent field are much longer than 15 years ago.
   This Memo proposes the Uniform User-Agent String as a way to simplify
   the User-Agent field contents, while maintaining the previous
   possibility of their use.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on May 14, 2015.

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Copyright Notice

   Copyright (c) 2014 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.

   This document may not be modified, and derivative works of it may not
   be created, except to format it for publication as an RFC or to
   translate it into languages other than English.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Conformance . . . . . . . . . . . . . . . . . . . . . . .   3
     1.2.  Syntax Notation . . . . . . . . . . . . . . . . . . . . .   3
       1.2.1.  Whitespaces . . . . . . . . . . . . . . . . . . . . .   3
   2.  Use of the User-Agent strings . . . . . . . . . . . . . . . .   3
   3.  Definition of Proposed Format . . . . . . . . . . . . . . . .   3
     3.1.  Standard String . . . . . . . . . . . . . . . . . . . . .   4
     3.2.  Regular String  . . . . . . . . . . . . . . . . . . . . .   4
     3.3.  Web Browser String  . . . . . . . . . . . . . . . . . . .   5
   4.  ABNF Definition of UUAS . . . . . . . . . . . . . . . . . . .   7
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   8
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   8
   7.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   8
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   8
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   9

1.  Introduction

   Nowadays User-Agent strings are long, complicated and often
   ambiguous. (e.g. "Mozilla/4.0 (compatible; MSIE 6.0; X11; Linux
   i686; en) Opera 8.01" - it is Opera Browser, but it can be read as
   Internet Explorer or Netscape Navigator.) This document specifies a
   new, easy and clear format of Unified User-Agent String (UUAS), which
   allows simple distinction between user agents, maintaining most of
   the features of the existing solutions.

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Internet-Draft          Unified User-Agent String          November 2014

1.1.  Conformance

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].