Edit comment LC-2091 for Mobile Web Best Practices Working Group

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Comment LC-2091

Comment Shortname:

Commenter: Luca Passani <passani@eunet.no>

Message-id:

Section of the document concerned:

[Free text description]Document as a wholeContent Transformation Guidelines 1.0 Abstract Status of this Document Table of Contents Appendices 1 Introduction (Non-Normative) 1.1 Purpose 1.2 Audience 1.3 Scope 1.4 Summary of Requirements 2 Terminology (Normative) 2.1 Types of Proxy "A transparent proxy is a proxy that does not modify the req... A non-transparent proxy is a proxy that modifies the request... 2.2 Types of Transformation Restructuring content is a process whereby the original layo... Recoding content is a process whereby the layout of the cont... Optimizing content includes removing redundant white space,... 3 Conformance (Normative) 3.1 Classes of Product 3.2 Normative and Informative Parts 3.3 Normative Language for Conformance Requirements 3.4 Content Deployment Conformance 3.5 Transformation Deployment Conformance 4 Behavior of Components (Normative) 4.1 Proxy Forwarding of Request 4.1.1 Applicable HTTP Methods 4.1.2 no-transform directive in Request 4.1.3 Treatment of Requesters that are not Web browsers 4.1.4 Serving Cached Responses 4.1.5 Alteration of HTTP Header Values In this section, the concept of "Web site" is used (rather t... 4.1.5.1 Content Tasting 4.1.5.2 Avoiding "Request Unacceptable" Responses 4.1.5.3 User Selection of Restructured Experience 4.1.5.4 Sequence of Requests 4.1.5.5 Original Headers 4.1.6 Additional HTTP Headers 4.1.6.1 Proxy Treatment of Via Header 4.2 Server Response to Proxy 4.2.1 Use of HTTP 406 Status 4.2.2 Server Origination of Cache-Control: no-transform Including a Cache-Control: no-transform directive can disrup... 4.2.3 Varying Representations 4.2.3.1 Use of Vary HTTP Header 4.2.3.2 Indication of Intended Presentation Media Type of Representation 4.3 Proxy Forwarding of Response to User Agent 4.3.1 Receipt of Cache-Control: no-transform 4.3.2 Receipt of Warning: 214 Transformation Applied 4.3.3 Server Rejection of HTTP Request 4.3.4 Receipt of Vary HTTP Header 4.3.5 Link to "handheld" Representation 4.3.6 Proxy Decision to Transform 4.3.6.1 Alteration of Response 4.3.6.2 HTTPS Link Re-writing 5 Testing (Normative) A References B Example Transformation Interactions (Non-Normative) B.1 Basic Content Tasting by Proxy B.2 Optimization based on Previous Server Interaction B.3 Optimization based on Previous Server Interaction, Server has Changed its Operation B.4 Server Response Indicating that this Representation is Intended for the Target Device B.5 Server Response Indicating that another Representation is Intended for the Target Device C Applicability to Transforming Solutions which are Out of Scope (Non-Normative) D Scope for Future Work (Non-Normative) D.1 POWDER D.2 link HTTP Header D.3 Sources of Device Information D.4 Inter Proxy Communication D.5 Amendment to and Refinement of HTTP E Administrative Arrangements (Non-Normative) F Acknowledgments (Non-Normative)
or

Refinement of the section concerned:

Status:

open proposal pending resolved_yes resolved_no resolved_partial other assigned to Nobody

Type: substantive editorial typo question general comment undefined

Resolution status:

Response drafted Resolution implemented Reply sent to commenter

Response status:

No response from Commenter yet Commenter approved disposition Commenter objected to disposition
Commenter's response (URI):

Comment:

Consistently with my other comment that no extra content should be added
to transcoded web sites, I think that this should apply even more
strongly to mobile-optimised sites. Unfortunately, I see a lot of
transcoder deployments where operators and/or transcoder vendors feel
entitled to add advertisement and extra navigation bars to existing
mobile optimisec ontent. Because of this, I suggest the following
addition as a note to "4.3.1":

"Note: It should be stressed that, in case of a |Cache-Control:
no-transform| directive, adding any extra content (such as banners,
navigation bars and links not available in the original application) is
not admissable"

Thank you

Luca Passani

Related issues: (space separated ids)

WG Notes: See: http://www.w3.org/2008/09/30-bpwg-minutes.html#item01 Also: http://www.w3.org/2008/09/30-bpwg-minutes.html#item05 Final resolutions: - The manner in which transformation is carried out, when it is permitted, including any additional navigational or other material that is included, aside from where explicitly stated (insecure links etc.) will be noted in an "out of scope section" in the document. And resolve no to LC-2090 and LC-2091 - Mention the out of scope nature of the details of restructuring under 4.3.6 somewhere (cf insertion of headers, footers etc.) Addendum: wonder why it's resolved "no". Should be resolved "partial".

Resolution: The Working Group agrees that adding any extra content to HTTP responses served with a Cache-Control: no-transform directive is not admissible. The Working Group notes that injection of extra content is an alteration of the response, and that alteration of an HTTP response served with a Cache-Contol: no-transform is explicitly forbidden: http://www.w3.org/TR/2009/WD-ct-guidelines-20091006/Overview.html#sec-receipt-of-cache-control-no-transform

(Please make sure the resolution is adapted for public consumption)