< draft-nottingham-rfc5785bis-04.txt		draft-nottingham-rfc5785bis-05.txt >
	Network Working Group M. Nottingham		Network Working Group M. Nottingham
	Internet-Draft February 15, 2018		Internet-Draft April 5, 2018
	Obsoletes: 5785 (if approved)		Obsoletes: 5785 (if approved)
	Intended status: Standards Track		Intended status: Standards Track
	Expires: August 19, 2018		Expires: October 7, 2018
	Defining Well-Known Uniform Resource Identifiers (URIs)		Defining Well-Known Uniform Resource Identifiers (URIs)
	draft-nottingham-rfc5785bis-04		draft-nottingham-rfc5785bis-05
	Abstract		Abstract
	This memo defines a path prefix for "well-known locations", "/.well-		This memo defines a path prefix for "well-known locations", "/.well-
	known/", in selected Uniform Resource Identifier (URI) schemes.		known/", in selected Uniform Resource Identifier (URI) schemes.
	Note to Readers		Note to Readers
	_RFC EDITOR: please remove this section before publication_		_RFC EDITOR: please remove this section before publication_
	skipping to change at page 2, line 4 ¶		skipping to change at page 2, line 4 ¶
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
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	This Internet-Draft will expire on August 19, 2018.		This Internet-Draft will expire on October 7, 2018.
	Copyright Notice		Copyright Notice
	Copyright (c) 2018 IETF Trust and the persons identified as the		Copyright (c) 2018 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
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	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
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	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
	1.1. Appropriate Use of Well-Known URIs . . . . . . . . . . . 3		2. Notational Conventions . . . . . . . . . . . . . . . . . . . 3
	2. Notational Conventions . . . . . . . . . . . . . . . . . . . 4		3. Well-Known URIs . . . . . . . . . . . . . . . . . . . . . . . 3
	3. Well-Known URIs . . . . . . . . . . . . . . . . . . . . . . . 4		3.1. Registering Well-Known URIs . . . . . . . . . . . . . . . 4
	4. Security Considerations . . . . . . . . . . . . . . . . . . . 5		4. Security Considerations . . . . . . . . . . . . . . . . . . . 5
	5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5		4.1. Interaction with the Web . . . . . . . . . . . . . . . . 5
	5.1. The Well-Known URI Registry . . . . . . . . . . . . . . . 5		4.2. Scoping Applications . . . . . . . . . . . . . . . . . . 6
	5.1.1. Registration Template . . . . . . . . . . . . . . . . 6		4.3. Hidden Capabilities . . . . . . . . . . . . . . . . . . . 7
	6. References . . . . . . . . . . . . . . . . . . . . . . . . . 6		5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
	6.1. Normative References . . . . . . . . . . . . . . . . . . 6		5.1. The Well-Known URI Registry . . . . . . . . . . . . . . . 7
	6.2. Informative References . . . . . . . . . . . . . . . . . 7		6. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
	6.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 7		6.1. Normative References . . . . . . . . . . . . . . . . . . 7
	Appendix A. Frequently Asked Questions . . . . . . . . . . . . . 8		6.2. Informative References . . . . . . . . . . . . . . . . . 8
	Appendix B. Changes from RFC5785 . . . . . . . . . . . . . . . . 8		6.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 9
	Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 9		Appendix A. Frequently Asked Questions . . . . . . . . . . . . . 9
			Appendix B. Changes from RFC5785 . . . . . . . . . . . . . . . . 10
			Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 10
	1. Introduction		1. Introduction
	Some applications on the Web require the discovery of information		Some applications on the Web require the discovery of information
	about an origin [RFC6454] (sometimes called "site-wide metadata")		about an origin [RFC6454] (sometimes called "site-wide metadata")
	before making a request. For example, the Robots Exclusion Protocol		before making a request. For example, the Robots Exclusion Protocol
	(http://www.robotstxt.org/ [5]) specifies a way for automated		(http://www.robotstxt.org/ [5]) specifies a way for automated
	processes to obtain permission to access resources; likewise, the		processes to obtain permission to access resources; likewise, the
	Platform for Privacy Preferences [W3C.REC-P3P-20020416] tells user-		Platform for Privacy Preferences [W3C.REC-P3P-20020416] tells user-
	agents how to discover privacy policy before interacting with an		agents how to discover privacy policy before interacting with an
	skipping to change at page 3, line 15 ¶		skipping to change at page 3, line 18 ¶
	difficulties) associated with them often precludes their use in these		difficulties) associated with them often precludes their use in these
	scenarios.		scenarios.
	When this happens, one solution is designating a "well-known		When this happens, one solution is designating a "well-known
	location" for data or services related to the origin overall, so that		location" for data or services related to the origin overall, so that
	it can be easily located. However, this approach has the drawback of		it can be easily located. However, this approach has the drawback of
	risking collisions, both with other such designated "well-known		risking collisions, both with other such designated "well-known
	locations" and with resources that the origin has created (or wishes		locations" and with resources that the origin has created (or wishes
	to create).		to create).
	To address this, this memo defines a path prefix in HTTP(S) URIs for		At the same time, it has become more popular to use HTTP as a
	these "well-known locations", "/.well-known/". Future specifications		substrate for non-Web protocols. Sometimes, such protocols need a
	that need to define a resource for such metadata can register their		way to locate one or more resources on a given host.
	use to avoid collisions and minimise impingement upon origins' URI
	space.		To address these uses, this memo defines a path prefix in HTTP(S)
			URIs for these "well-known locations", "/.well-known/". Future
			specifications that need to define a resource for such metadata can
			register their use to avoid collisions and minimise impingement upon
			origins' URI space.
	Well-known URIs can also be used with other URI schemes, but only		Well-known URIs can also be used with other URI schemes, but only
	when those schemes' definitions explicitly allow it.		when those schemes' definitions explicitly allow it.
	1.1. Appropriate Use of Well-Known URIs
	As per [RFC7320], "publishing independent standards that mandate
	particular forms of URI substructure is inappropriate, because that
	essentially usurps ownership." Well-known URIs are not an escape
	hatch from the requirements therein; they are a very limited carve-
	out of the path name space owned by the authority, ceded to standard
	use for a designated purpose.
	That purpose is to facilitate discovery of information about an
	origin when it isn't practical to use other mechanisms; for example,
	when discovering policy that needs to be evaluated before a resource
	is accessed, or when the information applies to many (or all) of the
	origin's resources.
	Typically, the resource(s) identified by a well-known URI will make
	information about the origin (e.g., policy) available directly, or
	provide references to other URIs that provide it. In general, that
	information should be applicable to most origins (i.e., Web sites -
	while acknowledging that some origins might not use a particular
	well-known location, for various reasons).
	In keeping with the Architecture of the World-Wide Web
	[W3C.REC-webarch-20041215], well-known URIs are not intended for
	general information retrieval or establishment of large URI
	namespaces.
	Specifically, well-known URIs are not a "protocol registry" for
	applications and protocols that wish to use HTTP as a substrate.
	Instead, such applications and protocols are encouraged to used an
	absolute URI to bootstrap their operation, rather than using a
	hostname and a well-known URI.
	Exceptionally, the registry expert(s) may approve such a registration
	for documents in the IETF Stream [RFC5741], in consultation with the
	IESG, provided that the protocol in question cannot be bootstrapped
	with a URI (e.g., the discovery mechanism can only carry a hostname).
	However, merely making it easier to locate it is not a sufficient
	reason. Likewise, future use unsupported by the specification in
	question is not sufficient reason to register a well-known location.
	Well-known locations are also not suited for information on topics
	other than the origin that they are located upon; for example,
	creating a well-known resource about a business entity or
	organisational structure presumes that Internet hosts and
	organisations share structure, and are likely to have significant
	deployment issues in environments where this is not true.
	2. Notational Conventions		2. Notational Conventions
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this		"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
	document are to be interpreted as described in RFC 2119 [RFC2119].		document are to be interpreted as described in RFC 2119 [RFC2119].
	3. Well-Known URIs		3. Well-Known URIs
	A well-known URI is a URI [RFC3986] whose path component begins with		A well-known URI is a URI [RFC3986] whose path component begins with
	the characters "/.well-known/", and whose scheme is "HTTP", "HTTPS",		the characters "/.well-known/", and whose scheme is "HTTP", "HTTPS",
	skipping to change at page 4, line 49 ¶		skipping to change at page 4, line 5 ¶
	Applications that wish to mint new well-known URIs MUST register		Applications that wish to mint new well-known URIs MUST register
	them, following the procedures in Section 5.1.		them, following the procedures in Section 5.1.
	For example, if an application registers the name 'example', the		For example, if an application registers the name 'example', the
	corresponding well-known URI on 'http://www.example.com/' would be		corresponding well-known URI on 'http://www.example.com/' would be
	'http://www.example.com/.well-known/example'.		'http://www.example.com/.well-known/example'.
	Registered names MUST conform to the segment-nz production in		Registered names MUST conform to the segment-nz production in
	[RFC3986]. This means they cannot contain the "/" character.		[RFC3986]. This means they cannot contain the "/" character.
	Note that this specification defines neither how to determine the		Registered names for a specific application SHOULD be correspondingly
	authority to use for a particular context, nor the scope of the		precise; "squatting" on generic terms is not encouraged. For
	metadata discovered by dereferencing the well-known URI; both should		example, if the Example application wants a well-known location for
	be defined by the application itself.		metadata, an appropriate registered name might be "example-metadata"
			or even "example.com-metadata", not "metadata".
	Typically, a registration will reference a specification that defines		At a minimum, a registration will reference a specification that
	the format and associated media type to be obtained by dereferencing		defines the format and associated media type to be obtained by
	the well-known URI.		dereferencing the well-known URI, along with the URI scheme(s) that
			the well-known URI can be used with. If no URI schemes are
			explicitly specified, "HTTP" and "HTTPS" are assumed.
	It MAY also contain additional information, such as the syntax of		It MAY also contain additional information, such as the syntax of
	additional path components, query strings and/or fragment identifiers		additional path components, query strings and/or fragment identifiers
	to be appended to the well-known URI, or protocol-specific details		to be appended to the well-known URI, or protocol-specific details
	(e.g., HTTP [RFC7231] method handling).		(e.g., HTTP [RFC7231] method handling).
	Note that this specification does not define a format or media-type		Note that this specification defines neither how to determine the
	for the resource located at "/.well-known/" and clients should not		hostname to use to find the well-known URI for a particular
	expect a resource to exist at that location.		application, nor the scope of the metadata discovered by
			dereferencing the well-known URI; both should be defined by the
			application itself.
			Also, this specification does not define a format or media-type for
			the resource located at "/.well-known/" and clients should not expect
			a resource to exist at that location.
	Well-known URIs are only valid when rooted in the top of the path's		Well-known URIs are only valid when rooted in the top of the path's
	hierarchy; they MUST NOT be used in other parts of the path. For		hierarchy; they MUST NOT be used in other parts of the path. For
	example, "/.well-known/example" is a valid use, but "/foo/.well-		example, "/.well-known/example" is a valid use, but "/foo/.well-
	known/example" is not.		known/example" is not.
	4. Security Considerations		See also Section 4 for Security Considerations regarding well-known
			locations.
	This memo does not specify the scope of applicability of metadata or		3.1. Registering Well-Known URIs
	policy obtained from a well-known URI, and does not specify how to
	discover a well-known URI for a particular application. Individual		The "Well-Known URIs" registry is located at
	applications using this mechanism must define both aspects.		"https://www.iana.org/assignments/well-known-uris/". Registration
			requests can be made by following the instructions located there or
			by sending an email to the "wellknown-uri-review@ietf.org" mailing
			list.
			Registration requests consist of at least the following information:
			URI suffix: The name requested for the well-known URI, relative to
			"/.well-known/"; e.g., "example".
			Change controller: For Standards-Track RFCs, state "IETF". For
			others, give the name of the responsible party. Other details
			(e.g., postal address, e-mail address, home page URI) may also be
			included.
			Specification document(s): Reference to the document that specifies
			the field, preferably including a URI that can be used to retrieve
			a copy of the document. An indication of the relevant sections
			may also be included, but is not required.
			Related information: Optionally, citations to additional documents
			containing further relevant information.
			General requirements for registered relation types are described in
			Section 3.
			Registrations MUST reference a freely available, stable
			specification.
			Note that well-known URIs can be registered by third parties
			(including the expert(s)), if the expert(s) determines that an
			unregistered well-known URI is widely deployed and not likely to be
			registered in a timely manner otherwise. Such registrations still
			are subject to the requirements defined, including the need to
			reference a specification.
			4. Security Considerations
	Applications minting new well-known URIs, as well as administrators		Applications minting new well-known URIs, as well as administrators
	deploying them, will need to consider several security-related		deploying them, will need to consider several security-related
	issues, including (but not limited to) exposure of sensitive data,		issues, including (but not limited to) exposure of sensitive data,
	denial-of-service attacks (in addition to normal load issues), server		denial-of-service attacks (in addition to normal load issues), server
	and client authentication, vulnerability to DNS rebinding attacks,		and client authentication, vulnerability to DNS rebinding attacks,
	and attacks where limited access to a server grants the ability to		and attacks where limited access to a server grants the ability to
	affect how well-known URIs are served.		affect how well-known URIs are served.
	Security-sensitive applications using well-known locations should		4.1. Interaction with the Web
	consider that some server administrators might be unaware of its
	existence (especially on operating systems that hide directories		In particular, applications using well-known URIs for HTTP or HTTPS
	whose names begin with "."). This means that if an attacker has		URLs need to be aware that well-known resources will be accessible to
	write access to the .well-known directory, they would be able to		Web browsers, and therefore is potentially able to be manipulated by
	control its contents, possibly without the administrator realising		content obtained from other parts of that origin. If an attacker is
	it.		able to inject content (e.g., through a Cross-Site Scripting
			vulnerability), they will be able to make potentially arbitrary
			requests to the well-known resource.
			HTTP and HTTPS also use origins as a security boundary for many other
			mechanisms, including (but not limited to) Cookies [RFC6265], Web
			Storage [W3C.REC-webstorage-20160419] and many capabilities.
			Applications defining well-known locations should not assume that
			they have sole access to these mechanisms.
			Applications defining well-known URIs should not assume or require
			that they are the only application using the origin, since this is a
			common deployment pattern; instead, they should use appropriate
			mechanisms to mitigate the risks of co-existing with Web
			applications, such as (but not limited to):
			o Using Strict Transport Security [RFC6797] to assure that HTTPS is
			used
			o Using Content-Security-Policy [W3C.WD-CSP3-20160913] to constrain
			the capabilities of content, thereby mitigating Cross-Site
			Scripting attacks (which are possible if client-provided data is
			exposed in any part of a response in the application)
			o Using X-Frame-Options [RFC7034] to prevent content from being
			included in a HTML frame from another origin, thereby enabling
			"clickjacking"
			o Using Referrer-Policy [W3C.CR-referrer-policy-20170126] to prevent
			sensitive data in URLs from being leaked in the Referer request
			header
			o Using the 'HttpOnly' flag on Cookies to assure that cookies are
			not exposed to browser scripting languages [RFC6265]
			4.2. Scoping Applications
			This memo does not specify the scope of applicability of metadata or
			policy obtained from a well-known URI, and does not specify how to
			discover a well-known URI for a particular application.
			Individual applications using this mechanism must define both
			aspects; if this is not specified, security issues can arise from
			implementation deviations and confusion about boundaries between
			applications.
			Applying metadata discovered in a well-known URI to resources other
			than those co-located on the same origin risks administrative as well
			as security issues. For example, allowing
			"https://example.com/.well-known/example" to apply policy to
			"https://department.example.com", "https://www.example.com" or even
			"https://www.example.com:8000" assumes a relationship between hosts
			where there may be none, or there may be conflicting motivations.
			4.3. Hidden Capabilities
			Applications using well-known locations should consider that some
			server administrators might be unaware of its existence (especially
			on operating systems that hide directories whose names begin with
			"."). This means that if an attacker has write access to the .well-
			known directory, they would be able to control its contents, possibly
			without the administrator realising it.
	5. IANA Considerations		5. IANA Considerations
	5.1. The Well-Known URI Registry		5.1. The Well-Known URI Registry
	This document specifies procedures for the well-known URI registry,		This specification updates the registration procedures for the "Well-
	first defined in [RFC5785].		Known URI" registry, first defined in [RFC5785]; see Section 3.1.
	Well-known URIs are registered on the advice of one or more experts		Well-known URIs are registered on the advice of one or more experts
	(appointed by the IESG or their delegate), with a Specification		(appointed by the IESG or their delegate), with a Specification
	Required (using terminology from [RFC8126]).		Required (using terminology from [RFC8126]).
	To allow for the allocation of values prior to publication, the		The Experts' primary considerations in evaluating registration
	expert(s) may approve registration once they are satisfied that such		requests are: * Conformance to the requirements in Section 3 * The
	a specification will be published.		availability and stability of the specifying document * The security
			considerations outlined in Section 4
	Registration requests can be sent to the wellknown-uri-
	review@ietf.org mailing list for review and comment, with an
	appropriate subject (e.g., "Request for well-known URI: example").
	5.1.1. Registration Template
	URI suffix: The name requested for the well-known URI, relative to
	"/.well-known/"; e.g., "example".
	Change controller: For Standards-Track RFCs, state "IETF". For
	others, give the name of the responsible party. Other details
	(e.g., postal address, e-mail address, home page URI) may also be
	included.
	Specification document(s): Reference to the document that specifies		IANA will direct any incoming requests regarding the registry to this
	the field, preferably including a URI that can be used to retrieve		document and, if defined, the processes established by the expert(s);
	a copy of the document. An indication of the relevant sections		typically, this will mean referring them to the registry Web page.
	may also be included, but is not required.
	Related information: Optionally, citations to additional documents		IANA should replace all references to RFC 5988 in that registry have
	containing further relevant information.		been replaced with references to this document.
	6. References		6. References
	6.1. Normative References		6.1. Normative References
	[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate		[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
	Requirement Levels", BCP 14, RFC 2119,		Requirement Levels", BCP 14, RFC 2119,
	DOI 10.17487/RFC2119, March 1997,		DOI 10.17487/RFC2119, March 1997,
	<https://www.rfc-editor.org/info/rfc2119>.		<https://www.rfc-editor.org/info/rfc2119>.
	[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform		[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
	Resource Identifier (URI): Generic Syntax", STD 66,		Resource Identifier (URI): Generic Syntax", STD 66,
	RFC 3986, DOI 10.17487/RFC3986, January 2005,		RFC 3986, DOI 10.17487/RFC3986, January 2005,
	<https://www.rfc-editor.org/info/rfc3986>.		<https://www.rfc-editor.org/info/rfc3986>.
	[RFC5741] Daigle, L., Ed., Kolkman, O., Ed., and IAB, "RFC Streams,
	Headers, and Boilerplates", RFC 5741,
	DOI 10.17487/RFC5741, December 2009,
	<https://www.rfc-editor.org/info/rfc5741>.
	[RFC6454] Barth, A., "The Web Origin Concept", RFC 6454,		[RFC6454] Barth, A., "The Web Origin Concept", RFC 6454,
	DOI 10.17487/RFC6454, December 2011,		DOI 10.17487/RFC6454, December 2011,
	<https://www.rfc-editor.org/info/rfc6454>.		<https://www.rfc-editor.org/info/rfc6454>.
	[RFC7320] Nottingham, M., "URI Design and Ownership", BCP 190,
	RFC 7320, DOI 10.17487/RFC7320, July 2014,
	<https://www.rfc-editor.org/info/rfc7320>.
	[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for		[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
	Writing an IANA Considerations Section in RFCs", BCP 26,		Writing an IANA Considerations Section in RFCs", BCP 26,
	RFC 8126, DOI 10.17487/RFC8126, June 2017,		RFC 8126, DOI 10.17487/RFC8126, June 2017,
	<https://www.rfc-editor.org/info/rfc8126>.		<https://www.rfc-editor.org/info/rfc8126>.
	6.2. Informative References		6.2. Informative References
	[RFC4918] Dusseault, L., Ed., "HTTP Extensions for Web Distributed		[RFC4918] Dusseault, L., Ed., "HTTP Extensions for Web Distributed
	Authoring and Versioning (WebDAV)", RFC 4918,		Authoring and Versioning (WebDAV)", RFC 4918,
	DOI 10.17487/RFC4918, June 2007,		DOI 10.17487/RFC4918, June 2007,
	<https://www.rfc-editor.org/info/rfc4918>.		<https://www.rfc-editor.org/info/rfc4918>.
	[RFC5785] Nottingham, M. and E. Hammer-Lahav, "Defining Well-Known		[RFC5785] Nottingham, M. and E. Hammer-Lahav, "Defining Well-Known
	Uniform Resource Identifiers (URIs)", RFC 5785,		Uniform Resource Identifiers (URIs)", RFC 5785,
	DOI 10.17487/RFC5785, April 2010,		DOI 10.17487/RFC5785, April 2010,
	<https://www.rfc-editor.org/info/rfc5785>.		<https://www.rfc-editor.org/info/rfc5785>.
			[RFC6265] Barth, A., "HTTP State Management Mechanism", RFC 6265,
			DOI 10.17487/RFC6265, April 2011,
			<https://www.rfc-editor.org/info/rfc6265>.
			[RFC6797] Hodges, J., Jackson, C., and A. Barth, "HTTP Strict
			Transport Security (HSTS)", RFC 6797,
			DOI 10.17487/RFC6797, November 2012,
			<https://www.rfc-editor.org/info/rfc6797>.
			[RFC7034] Ross, D. and T. Gondrom, "HTTP Header Field X-Frame-
			Options", RFC 7034, DOI 10.17487/RFC7034, October 2013,
			<https://www.rfc-editor.org/info/rfc7034>.
	[RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer		[RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
	Protocol (HTTP/1.1): Semantics and Content", RFC 7231,		Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
	DOI 10.17487/RFC7231, June 2014,		DOI 10.17487/RFC7231, June 2014,
	<https://www.rfc-editor.org/info/rfc7231>.		<https://www.rfc-editor.org/info/rfc7231>.
			[W3C.CR-referrer-policy-20170126]
			Eisinger, J. and E. Stark, "Referrer Policy", World Wide
			Web Consortium CR CR-referrer-policy-20170126, January
			2017,
			<https://www.w3.org/TR/2017/CR-referrer-policy-20170126>.
	[W3C.REC-P3P-20020416]		[W3C.REC-P3P-20020416]
	Marchiori, M., "The Platform for Privacy Preferences 1.0		Marchiori, M., "The Platform for Privacy Preferences 1.0
	(P3P1.0) Specification", World Wide Web Consortium		(P3P1.0) Specification", World Wide Web Consortium
	Recommendation REC-P3P-20020416, April 2002,		Recommendation REC-P3P-20020416, April 2002,
	<http://www.w3.org/TR/2002/REC-P3P-20020416>.		<http://www.w3.org/TR/2002/REC-P3P-20020416>.
	[W3C.REC-webarch-20041215]		[W3C.REC-webstorage-20160419]
	Jacobs, I. and N. Walsh, "Architecture of the World Wide		Hickson, I., "Web Storage (Second Edition)", World Wide
	Web, Volume One", World Wide Web Consortium		Web Consortium Recommendation REC-webstorage-20160419,
	Recommendation REC-webarch-20041215, December 2004,		April 2016,
	<http://www.w3.org/TR/2004/REC-webarch-20041215>.		<http://www.w3.org/TR/2016/REC-webstorage-20160419>.
			[W3C.WD-CSP3-20160913]
			West, M., "Content Security Policy Level 3", World Wide
			Web Consortium WD WD-CSP3-20160913, September 2016,
			<https://www.w3.org/TR/2016/WD-CSP3-20160913>.
	6.3. URIs		6.3. URIs
	[1] https://github.com/mnot/I-D/labels/rfc5785bis		[1] https://github.com/mnot/I-D/labels/rfc5785bis
	[2] https://mnot.github.io/I-D/rfc5785bis/		[2] https://mnot.github.io/I-D/rfc5785bis/
	[3] https://github.com/mnot/I-D/commits/gh-pages/rfc5785bis		[3] https://github.com/mnot/I-D/commits/gh-pages/rfc5785bis
	[4] https://datatracker.ietf.org/doc/draft-nottingham-rfc5785bis/		[4] https://datatracker.ietf.org/doc/draft-nottingham-rfc5785bis/
	skipping to change at page 8, line 38 ¶		skipping to change at page 10, line 13 ¶
	None, until they choose to use this mechanism.		None, until they choose to use this mechanism.
	4. Why aren't per-directory well-known locations defined?		4. Why aren't per-directory well-known locations defined?
	Allowing every URI path segment to have a well-known location		Allowing every URI path segment to have a well-known location
	(e.g., "/images/.well-known/") would increase the risks of		(e.g., "/images/.well-known/") would increase the risks of
	colliding with a pre-existing URI on a site, and generally these		colliding with a pre-existing URI on a site, and generally these
	solutions are found not to scale well, because they're too		solutions are found not to scale well, because they're too
	"chatty".		"chatty".
	5. I want to use a well-known location to make it easy to configure
	my protocol that uses HTTP.
	This is not what well-known locations are for; see Section 1.1.
	Appendix B. Changes from RFC5785		Appendix B. Changes from RFC5785
	o Discuss appropriate and inappropriate uses more fully		o Allow non-Web well-known locations
	o Adjust IANA instructions		o Adjust IANA instructions
	o Update references		o Update references
	o Various other clarifications		o Various other clarifications
	Author's Address		Author's Address
	Mark Nottingham		Mark Nottingham
End of changes. 25 change blocks.
	137 lines changed or deleted		198 lines changed or added
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