draft-ietf-appsawg-about-uri-scheme-07.txt   rfc6694.txt 
Applications Area WG (APPSAWG) S. Moonesamy, Ed. Internet Engineering Task Force (IETF) S. Moonesamy, Ed.
Internet-Draft Request for Comments: 6694 August 2012
Intended Status: Informational Category: Informational
Expires: December 9, 2012 June 7, 2012 ISSN: 2070-1721
The "about" URI Scheme The "about" URI Scheme
draft-ietf-appsawg-about-uri-scheme-07
Abstract Abstract
This document describes the "about" URI scheme, which is widely used This document describes the "about" URI scheme, which is widely used
by web browsers and some other applications to designate access to by Web browsers and some other applications to designate access to
their internal resources, such as settings, application information, their internal resources, such as settings, application information,
hidden built-in functionality, and so on. hidden built-in functionality, and so on.
Status of this Memo Status of This Memo
This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as
Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six months This document is not an Internet Standards Track specification; it is
and may be updated, replaced, or obsoleted by other documents at any published for informational purposes.
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at This document is a product of the Internet Engineering Task Force
http://www.ietf.org/1id-abstracts.html (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.
The list of Internet-Draft Shadow Directories can be accessed at Information about the current status of this document, any errata,
http://www.ietf.org/shadow.html and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc6694.
Copyright and License Notice Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction ....................................................2
2. URI Scheme Specification . . . . . . . . . . . . . . . . . . . 2 2. URI Scheme Specification ........................................2
2.1. URI Scheme Syntax . . . . . . . . . . . . . . . . . . . . . 2 2.1. URI Scheme Syntax ..........................................2
2.2. URI Scheme Semantics . . . . . . . . . . . . . . . . . . . 2 2.2. URI Scheme Semantics .......................................3
2.2.1. Well-known "about" URIs . . . . . . . . . . . . . . . . 3 2.2.1. Well-Known "about" URIs .............................3
2.3. Encoding Considerations . . . . . . . . . . . . . . . . . . 3 2.3. Encoding Considerations ....................................3
3. "about:blank" . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. "about:blank" ...................................................3
4. Security Considerations . . . . . . . . . . . . . . . . . . . . 3 4. Security Considerations .........................................3
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 5. IANA Considerations .............................................4
5.1. URI Scheme Registration . . . . . . . . . . . . . . . . . . 4 5.1. URI Scheme Registration ....................................4
5.2. A Registry for Well-known Tokens . . . . . . . . . . . . . 4 5.2. A Registry for Well-Known Tokens ...........................5
5.2.1. Registration procedure . . . . . . . . . . . . . . . . 5 5.2.1. Registration Procedure ..............................5
6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5 6. References ......................................................6
6.1. Normative References . . . . . . . . . . . . . . . . . . . 5 6.1. Normative References .......................................6
6.2. Informative References . . . . . . . . . . . . . . . . . . 6 6.2. Informative References .....................................6
Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . . 6 Appendix A. Acknowledgments ........................................7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction 1. Introduction
This document describes the "about" Uniform Resource Identifier (URI) This document describes the "about" Uniform Resource Identifier (URI)
scheme. The "about" URI scheme is currently widely used by Web scheme. The "about" URI scheme is currently widely used by Web
browsers to designate access to their internal resources such as browsers to designate access to their internal resources, such as
settings, application information, so called "Easter eggs" (i.e. settings, application information, and so-called "Easter eggs" (i.e.,
hidden feature or joke in an application). a hidden feature or joke in an application).
2. URI Scheme Specification 2. URI Scheme Specification
2.1. URI Scheme Syntax 2.1. URI Scheme Syntax
The "about" URI syntactically conforms to the <about-uri> rule below, The "about" URI syntactically conforms to the <about-uri> rule below,
expressed using Augmented Backus-Naur Form (ABNF) [RFC5234]: expressed using the Augmented Backus-Naur Form (ABNF) [RFC5234]:
about-uri = "about:" about-token [ about-query ] [ about-fragment ] about-uri = "about:" about-token [ about-query ] [ about-fragment ]
about-token = *pchar about-token = *pchar
about-query = "?" query about-query = "?" query
about-fragment = "#" fragment about-fragment = "#" fragment
pchar = <as specified in RFC 3986, Appendix A> pchar = <as specified in RFC 3986, Appendix A>
query = <as specified in RFC 3986, Appendix A> query = <as specified in RFC 3986, Appendix A>
fragment = <as specified in RFC 3986, Appendix A> fragment = <as specified in RFC 3986, Appendix A>
2.2. URI Scheme Semantics 2.2. URI Scheme Semantics
The resource which a particular "about" URI references is denoted
by <about-token> part of the URI. It is not a hierarchical element
for a naming authority. The <about-query> specifies additional
information about its handling and/or the information that should
be returned by the resource which the URI references.
It is impossible to specify a binding between all the possible The resource that is referenced by a particular "about" URI is
tokens and the semantics of "about" URIs that would contain such denoted by the <about-token> part of the URI. It is not a
tokens. Therefore the resource referenced by the URI is generally hierarchical element for a naming authority. The <about-query> part
considered as specific to a Web browser implementation. specifies additional information about its handling and/or the
information that should be returned by the resource referenced by
the URI.
2.2.1. Well-known "about" URIs It is impossible to specify a binding between all the possible tokens
and the semantics of "about" URIs that would contain such tokens.
Therefore, the resource referenced by the URI is generally considered
to be specific to a Web browser implementation.
Some <about-token>s have been reserved as the behavior when the 2.2.1. Well-Known "about" URIs
resource is referenced is well-known (Well-known tokens).
A well-known "about" URI is a URI that has a well-known token as Some <about-token>s have been reserved, as the behavior of the
its <about-token> part. It is recommended that such URIs be resource that is referenced is well-known (well-known tokens).
handled in accordance with the specification referenced in the
Well-known Tokens registry (see Section 5.2).
Well-known "about" URIs are intended to be registered when there is A well-known "about" URI is a URI that has a well-known token as its
a need to codify the behavior of particular <about-token>. <about-token> part. It is recommended that such URIs be handled in
accordance with the specification referenced in the "about" URI
Tokens registry (see Section 5.2).
2.3. Encoding Considerations Well-known "about" URIs are intended to be registered when there is a
need to codify the behavior of a particular <about-token>.
"about" URIs are subject to encoding rules defined in RFC 3986 2.3. Encoding Considerations
[RFC3986].
3. "about:blank" "about" URIs are subject to encoding rules as defined in RFC 3986
[RFC3986].
This document defines one well-known token: "blank". The 3. "about:blank"
"about:blank" URI refers to a resource represented in the browser
by a blank page.
4. Security Considerations This document defines one well-known token: "blank". The
"about:blank" URI refers to a resource represented in the browser by
a blank page.
Security considerations for URIs are discussed in Section 7 of RFC 4. Security Considerations
3986 [RFC3986]. However, most of those provisions do not apply to
the "about" URI scheme as they are mainly scoped to schemes used in
the Internet.
"about" URIs can sometimes refer to sensitive information, such as Security considerations for URIs are discussed in Section 7 of
user passwords stored in a cache, or parameters that, if changed, RFC 3986 [RFC3986]. However, most of those provisions do not apply
could affect user's data. The application therefore needs to to the "about" URI scheme, as they are mainly scoped to schemes used
ensure that the user's data is secured and no threats are imposed in the Internet.
by "about" URIs.
5. IANA Considerations "about" URIs can sometimes refer to sensitive information, such as
user passwords stored in a cache, or parameters that, if changed,
could affect a user's data. The application therefore needs to
ensure that the user's data is secured and no threats are imposed by
"about" URIs.
5.1. URI Scheme Registration 5. IANA Considerations
The registration of the "about" URI scheme in the "URI Schemes" 5.1. URI Scheme Registration
registry is requested. The information below is provided according
to the guidelines from RFC 4395 [RFC4395]:
URI scheme name: about The "about" URI scheme has been registered in the "Permanent URI
Schemes" registry. The information below is provided according to
the guidelines from RFC 4395 [RFC4395]:
Status: Permanent URI scheme name: about
URI scheme syntax: see Section 2.1 of RFC xxxx Status: Permanent
URI scheme semantics: see Section 2.2 of RFC xxxx URI scheme syntax: See Section 2.1 of RFC 6694.
URI scheme encoding considerations: see Section 2.3 of RFC xxxx URI scheme semantics: See Section 2.2 of RFC 6694.
Applications that use the scheme: "about" URIs are predominantly URI scheme encoding considerations: See Section 2.3 of RFC 6694.
used by Web browsers.
Security considerations: see Section 4 of RFC xxxx Applications that use the scheme: "about" URIs are predominantly
used by Web browsers.
Contact: IETF Applications Area Directors <app-ads@tools.ietf.org> Security considerations: See Section 4 of RFC 6694.
Author/Change controller: IESG <iesg@ietf.org> (on behalf of the Contact: IETF Applications Area Directors
IETF) <app-ads@tools.ietf.org>
References: see Section 5 of RFC xxxx Author/Change controller: IESG <iesg@ietf.org> (on behalf of the
IETF)
[RFC Editor: Please replace xxxx with assigned RFC number] References: See Section 6 of RFC 6694.
5.2. A Registry for Well-known Tokens 5.2. A Registry for Well-Known Tokens
This document creates the '"about" URI Well-known Tokens' registry. This document creates the '"about" URI Tokens' registry.
The registry entries consist of three fields: Well-known Token, The registry entries consist of three fields: Token, Description, and
Description and Reference. The Well-known Token field has to conform Reference. The Token field has to conform to <about-token>
to <about-token> production defined in Section 2.1. The initial set production as defined in Section 2.1. The initial assignment is as
of assignments is as follows: follows:
+--------------+------------------------------------+-------------+ +--------------+------------------------------------+-------------+
| Well-known | Description | Reference | | Token | Description | Reference |
| Token | | | +--------------+------------------------------------+-------------+
+------------------+--------------------------------+-------------+ | blank | The about:blank URI references a | RFC 6694 |
| blank | The about:blank URI references a | RFC xxxx |
| | blank page. | | | | blank page. | |
+--------------+------------------------------------+-------------+ +--------------+------------------------------------+-------------+
5.2.1. Registration procedure 5.2.1. Registration Procedure
The registration policy for this registry is "First Come First The registration policy for this registry is "First Come First
Served" as described in RFC 5226 [RFC5226]. The registrant of the Served", as described in RFC 5226 [RFC5226]. The registrant of the
token should provide the information mentioned in the following token should provide the information mentioned in the following
registration template: registration template:
o Registered Token: The desired Well-known token to be used in o Registered token: The desired well-known token to be used in
"about" URIs. "about" URIs.
o Intended usage: A short description of how "about" URIs with the o Intended usage: A short description of how "about" URIs with the
registered token is handled including information about the registered token are handled, including information about the
referenced resource. referenced resource.
o Contact/Change controller: Person (including contact information) o Contact/change controller: Person (including contact information)
authorized to change this registration. authorized to change this registration.
o Specification: A stable reference to a document which specifies o Specification: A stable reference to a document that specifies
the registered "about" URI. The question of interoperability does the registered "about" URI. The question of interoperability does
not arise. The key motivation is to have a reference to a not arise. The key motivation is to have a reference to a
specification documenting well-known behavior of the "about" URI in specification documenting well-known behavior of the "about" URI
Web browsers. As a rule of thumb if the behavior is common to two in Web browsers. As a rule of thumb, if the behavior is common to
or more Web browser implementations it can be considered as well- two or more Web browser implementations, it can be considered
known. An existing assignment may be duplicated if the registered well-known. An existing assignment may be duplicated if the
token is used in more than one Web browser implementation. registered token is used in more than one Web browser
implementation.
The following is a template for the "blank" token: The following is a template for the "blank" token:
o Registered Token: blank o Registered token: blank
o Intended usage: The about:blank URI references a blank page.
o Contact/Change controller: IESG <iesg@ietf.org> (on behalf of
IETF).
o Specification: RFC xxxx. [RFC Editor: Please replace xxxx with
assigned RFC number]
6. References o Intended usage: The about:blank URI references a blank page.
6.1. Normative References o Contact/change controller: IESG <iesg@ietf.org> (on behalf of the
IETF).
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform o Specification: RFC 6694
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, January 2005.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 6. References
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
[RFC5234] Crocker, D., Ed., and P. Overell, "Augmented BNF for 6.1. Normative References
Syntax Specifications: ABNF", STD 68, RFC 5234, January
2008.
6.2. Informative References [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, January 2005.
[RFC4395] Hansen, T., Hardie, T., and L. Masinter, "Guidelines and [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
Registration Procedures for New URI Schemes", BCP 35, IANA Considerations Section in RFCs", BCP 26, RFC 5226,
RFC 4395, February 2006. May 2008.
[RFC5234] Crocker, D., Ed., and P. Overell, "Augmented BNF for
Syntax Specifications: ABNF", STD 68, RFC 5234,
January 2008.
6.2. Informative References
[RFC4395] Hansen, T., Hardie, T., and L. Masinter, "Guidelines and
Registration Procedures for New URI Schemes", BCP 35,
RFC 4395, February 2006.
Appendix A. Acknowledgments Appendix A. Acknowledgments
This document has been formed from the draft initially authored by This document was formed from a previous draft document initially
Lachlan Hunt and Joseph Holsten. Additionally, the contributions of authored by Lachlan Hunt and Joseph Holsten. Additionally, the
Frank Ellermann and Alexey Melnikov are gratefully acknowledged. contributions of Frank Ellermann and Alexey Melnikov are gratefully
Barry Leiba and Murray Kucherawy deserve a special credit for acknowledged. Barry Leiba and Murray Kucherawy deserve special
providing a great amount of text which has been used in this credit for providing a great amount of text that was used in this
document. document.
Lachlan Hunt and Mykyta Yevstifeyev edited previous versions of this Lachlan Hunt and Mykyta Yevstifeyev edited previous versions of this
document. Tim Bray and John Klensin provided suggestions about how document. Tim Bray and John Klensin provided suggestions about how
to improve the document. to improve the document.
Authors' Addresses Author's Address
S. Moonesamy (editor) S. Moonesamy (editor)
76, Ylang Ylang Avenue 76 Ylang Ylang Avenue
Quatre Bornes Quatre Bornes
Mauritius Mauritius
EMail: sm+ietf@elandsys.com EMail: sm+ietf@elandsys.com
 End of changes. 65 change blocks. 
160 lines changed or deleted 156 lines changed or added

This html diff was produced by rfcdiff 1.41. The latest version is available from http://tools.ietf.org/tools/rfcdiff/