Internet Engineering Task Force (IETF) S. Moonesamy, Ed.
Request for Comments: 6694 August 2012
Category: Informational
ISSN: 2070-1721
The "about" URI Scheme
Abstract
This document describes the "about" URI scheme, which is widely used
by Web browsers and some other applications to designate access to
their internal resources, such as settings, application information,
hidden built-in functionality, and so on.
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/rfc6694.
Copyright Notice
Copyright (c) 2012 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
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Moonesamy Informational [Page 1]
RFC 6694 The "about" URI Scheme August 2012
Table of Contents
1. Introduction ....................................................2
2. URI Scheme Specification ........................................2
2.1. URI Scheme Syntax ..........................................2
2.2. URI Scheme Semantics .......................................3
2.2.1. Well-Known "about" URIs .............................3
2.3. Encoding Considerations ....................................3
3. "about:blank" ...................................................3
4. Security Considerations .........................................3
5. IANA Considerations .............................................4
5.1. URI Scheme Registration ....................................4
5.2. A Registry for Well-Known Tokens ...........................5
5.2.1. Registration Procedure ..............................5
6. References ......................................................6
6.1. Normative References .......................................6
6.2. Informative References .....................................6
Appendix A. Acknowledgments ........................................7
1. Introduction
This document describes the "about" Uniform Resource Identifier (URI)
scheme. The "about" URI scheme is currently widely used by Web
browsers to designate access to their internal resources, such as
settings, application information, and so-called "Easter eggs" (i.e.,
a hidden feature or joke in an application).
2. URI Scheme Specification
2.1. URI Scheme Syntax
The "about" URI syntactically conforms to the <about-uri> rule below,
expressed using the Augmented Backus-Naur Form (ABNF) [RFC5234]:
about-uri = "about:" about-token [ about-query ] [ about-fragment ]
about-token = *pchar
about-query = "?" query
about-fragment = "#" fragment
pchar = <as specified in RFC 3986, Appendix A>
query = <as specified in RFC 3986, Appendix A>
fragment = <as specified in RFC 3986, Appendix A>
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RFC 6694 The "about" URI Scheme August 2012
2.2. URI Scheme Semantics
The resource that is referenced by a particular "about" URI is
denoted by the <about-token> part of the URI. It is not a
hierarchical element for a naming authority. The <about-query> part
specifies additional information about its handling and/or the
datatracker.ietf.org