Network Working Group Y. Shafranovich Internet-Draft SolidMatrix Technologies, Inc. Expires: November 14, 2005 May 13, 2005 An Extensible Format for Email Feedback Reports draft-shafranovich-feedback-report-01.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of 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 and may be updated, replaced, or obsoleted by other documents at any 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 http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on November 14, 2005. Copyright Notice Copyright (C) The Internet Society (2005). Abstract This document defines an extensible format and MIME type that may be used by network operators to report feedback about received email to other parties. This format is intended as a machine readable replacement for various existing report formats currently used in Internet email. Shafranovich Expires November 14, 2005 [Page 1] Internet-Draft Format for Feedback Reports May 2005 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Intent . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Format of Email Feedback Reports . . . . . . . . . . . . . . 4 5. Format of 'message/feedback-report' Content Type . . . . . . 5 5.1 Required Fields . . . . . . . . . . . . . . . . . . . . . 5 5.2 Optional Fields Appearing Once . . . . . . . . . . . . . . 6 5.3 Optional Fields Appearing Multiple Times . . . . . . . . . 6 6. MIME Type Registration of message/feedback-report . . . . . 7 7. Extensibility . . . . . . . . . . . . . . . . . . . . . . . 8 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . 8 8.1 Initial Values for the Header Names Registry . . . . . . . 9 8.2 Initial values for the "Feedback-Type" registry . . . . . 10 9. Security Considerations . . . . . . . . . . . . . . . . . . 11 10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . 11 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 11.1 Normative References . . . . . . . . . . . . . . . . . . 11 11.2 Informative References . . . . . . . . . . . . . . . . . 12 Author's Address . . . . . . . . . . . . . . . . . . . . . . 12 A. Appendix A - Sample Feedback Reports . . . . . . . . . . . . 12 A.1 Simple Report for Email Abuse without Optional Headers . . 12 A.2 Opt-Out Report without Message Body . . . . . . . . . . . 13 A.3 Full Report for Email Abuse with All Headers . . . . . . . 14 B. Status of This Document [To Be Removed Upon Publication] . . 16 B.1 Discussion Venue . . . . . . . . . . . . . . . . . . . . . 16 B.2 Document Repository and Public Website . . . . . . . . . . 16 B.3 Document History . . . . . . . . . . . . . . . . . . . . . 16 B.4 Outstanding Issues . . . . . . . . . . . . . . . . . . . . 17 Intellectual Property and Copyright Statements . . . . . . . 19 Shafranovich Expires November 14, 2005 [Page 2] Internet-Draft Format for Feedback Reports May 2005 1. Introduction As the spam problem has grown in the past few years, network operators have begun to exchange abuse reports among themselves and other parties to combat this problem. However, different operators define their own formats and the receivers are forced to write custom software to interpret the many types of them. In addition, many operators use various other report formats to provide non-abuse feedback about processed email. This memo seeks to define a standard extensible format and the "message/feedback-report" MIME type for these reports in accordance with RFC 2048 [11]. This format and content type is intended to be used within the scope of the framework of the "multipart/report" content type defined in RFC 3462 [1]. While there have been previous work in this area([12] and [13]), none of them have yet been sucessful. It is hoped that this document will have a better fate. This format is intended primarily as an Abuse Reporting Format (ARF) for reporting email abuse but also includes support for feedback loops, virus reports and other similar activities. This document only defines the format and content type to be used for these reports. Determination of where these reports should be sent, how trust among report senders and receivers is established, and reports related to more than one message are outside the scope of this document. 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 RFC 2119 [2]. NOTE: This document may be incomplete and is intented to evolve based on public discussion and feedback. Readers are encourages to submit their comments and suggestions. 2. Intent The reports defined in this document are intended for several purposes: o To inform ISPs about email abuse originating from or related to their networks o To provide feedback about abuse complaints to email service providers and relevant third parties (such as reputation providers) Shafranovich Expires November 14, 2005 [Page 3] Internet-Draft Format for Feedback Reports May 2005 o To inform email service provides about opt-out requests Please note that while the parent "multipart/report" content type defined in RFC 3462 [1] is used for all kinds of administrative messages, this format is intended specifically for communications among providers regarding email abuse and related issues, and SHOULD NOT be used for other reports. 3. Requirements The following requirements are necessary for feedback reports (the actual standard is defined in the next sections) : o They must be both human and machine readable o A copy of the original email message (body and headers) or the message headers must be enclosed in order to allow the receiver to properly handle the report. o The machine readable section must provide ability for the report generators to share metadata with receivers, o The format must be extensible. 4. Format of Email Feedback Reports To satisfy the requirements, an email feedback report is defined as a MIME message with a top level MIME content type of "multipart/report" (as defined in RFC 3462 [1]). The following apply: a. The "report-type" parameter of "multipart/report" type is set to "feedback-report" b. The first MIME part of the message contains a human readable description of the report and MUST be included. c. The second MIME part of the message is a machine-readable section with the content type of "message/feedback-report" (defined later on in this document) and MUST be included. This section is intended to convey metadata about the report in question that may not be readily available from the included email message itself. d. The third MIME part of the message contains either a full copy of the original message with a MIME content type of "message/rfc822" (as defined in RFC 2046 [3]) OR a copy of the headers from the original message with MIME content type of "text/rfc822-headers" (as defined in RFC 3462 [1]). This part MUST BE included (unlike Shafranovich Expires November 14, 2005 [Page 4] Internet-Draft Format for Feedback Reports May 2005 RFC 3462 [1]). While some operators may choose to modify or munge this portion for privacy or legal reasons, it is RECOMMENDED that the entire original email message be included without any modification. e. Each feedback report MUST be related to only a SINGLE email message. Summary and aggregate formats are outside the scope of this specification. f. The subject line of the feedback report SHOULD be the same as the included email message and MAY include only the standard forwarding prefix used by MUAs such as "FW:" (many smaller operators using MUAs for abuse handling rely on the subject lines for processing). 5. Format of 'message/feedback-report' Content Type This content type provides a machine-readable section intended to let the report generator convey metadata to the report receiver. The intent of this section is it allow report generators to convey metadata to report receivers that may not available or may not be readily available from the originating email message or headers. The body of this content type consists of multiple "fields" formatted according to the ABNF of RFC 822 [14] header "fields". This section defines the initial set of fields provided by this specification. Additional fields maybe registered according to the procedure described later on in this document. Note that these fields represent information that the receiver is asserting about the report in question, but are not necessarily verifiable. Report receivers MUST NOT assume that these assertions are always true. 5.1 Required Fields The following header fields are REQUIRED and MUST only appear once: o "Feedback-Type:" - contains the type of feedback report (as defined in the corresponding IANA registry). This is intended to let report generators distinguish among different types of reports. o "User-Agent:" - indicates the name and version of the software program that generated the report. The format of this field MUST follow section 14.43 of RFC 2616 [4]. o "Version" - indicates the version of specification that the report generator is using to generate the report. The version number in Shafranovich Expires November 14, 2005 [Page 5] Internet-Draft Format for Feedback Reports May 2005 this specification is set to "0.1". 5.2 Optional Fields Appearing Once The following header fields are OPTIONAL and MUST NOT appear more than once: o "Original-Mail-From:" - copy of the email address used in the MAIL FROM portion of the original SMTP transaction. The format of this field is defined in section 4.1.1.2 of RFC 2821 [5]. o "Original-Rcpt-To:" - copy of the email address used in the RCPT TO portion of the original SMTP transaction. The format of this field is defined in section 4.1.1.3 of RFC 2821 [5]. o "Received-Date:" - indicates the date the original message was received by the report generator. This field MUST BE formatted as per section 3.3 of RFC 2822 [6]. o "Source-IP:" - contains an IPv4 or IPv6 address of the MTA from which the original message was received. IPv4 addresses are to be formatted in dot-decimal notation as currently used by the community. IPv6 addresses MUST BE formatted as per section 2.2 of RFC 2373 [7]. 5.3 Optional Fields Appearing Multiple Times The following set of header fields are OPTIONAL and MAY appear more than once: o "Authentication-Results:" - indicates the result of an authentication check run by the report generator. The format of this field is is defined in draft-kucherawy-sender-auth-header [8]. Report receivers should note that this field only indicates an assertion made by the report generator. o "Reported-Domain:" - indicates a domain name that the report generator believes to be relevant to the report. Domain format is defined in section 2.3.1 of RFC 1035 [9]. o "Reported-URI:" - indicates a URI that the report generator believes to be relevant to the report. URI format is defined in RFC 2396 [15]. o "Removal-Recipient:" - indicates the email address to be removed from the mailing list (MUST only be used with "opt-out" and "opt- Shafranovich Expires November 14, 2005 [Page 6] Internet-Draft Format for Feedback Reports May 2005 out-list" types). The format of this field is defined in section 3.4.1 of RFC 2822 [6]. 6. MIME Type Registration of message/feedback-report This section provides the media type registration application (as per RFC 2048 [11], which will be submitted to IANA after IESG approval of this document. To: ietf-types@iana.org Subject: Registration of MIME media types message/feedback-report MIME media type name: message MIME subtype name: feedback-report Required parameters: none Optional parameters: none Encoding considerations: "7bit" encoding is sufficient and MUST be used to maintain readability when viewed by non-MIME mail readers. Security considerations: See the "Security Considerations" of this document. Interoperability considerations: implementors MUST ignore any fields they do not support Published specification: this document Applications which use this media type: Abuse helpdesk software for ISPs Additional information: Magic number(s): none File extension(s): none Macintosh File Type Code(s): none Person and email address to contact for further information: Shafranovich Expires November 14, 2005 [Page 7] Internet-Draft Format for Feedback Reports May 2005 Yakov Shafranovich Intended usage: COMMON Author/Change controller: IESG 7. Extensibility Like many other formats and protocols, this format may need to be extended overtime to fit the ever changing landscape of the Internet. Therefore, extensibility is being provided via two IANA registries: one for feedback types and a second for header fields. The feedback type registry is to be used in conjunction with the "Feedback-Type" field above. The header name registry is intended for registration of new metadata fields to be used in the machine readable portion (part 2) of this format. Please note that version numbers do not change with new field registrations unless a new specification of this format is published. Also note that all new field registrations can only registered OPTIONAL fields. Any new required fields REQUIRE a new version of this specification to be published. In order to encourage extensibility and interoperability of this format, implementors SHOULD ignore any fields they do not support. 8. IANA Considerations After IESG approval, IANA is expected to register MIME type "message/ feedback-report" using the application provided in this document and setup two registries: one for header field names and a second for "Feedback-Type" values. This section contains the templates used for registration of new entries in these registries and initial values. New registrations to these two registries MUST have approval by an Designated Expert in accordance with the Expert Review guidelines as described in RFC 2434 [10] (the expert should be appointed by the Area Directors of the Applications Area). Any new field registered is considered OPTIONAL unless a new version of this specification is published. For the header name registry, the following MUST be provided in an RFC publication (or Internet draft with IETF consensus or IESG approval) in order to register a new header field name: 1. Name of the field being registered 2. Short description of the field 3. Whether the field can appear more than once Shafranovich Expires November 14, 2005 [Page 8] Internet-Draft Format for Feedback Reports May 2005 4. Which "Feedback-Type" types does this field apply to (or "any") 5. The RFC number (or Internet draft name) in which this header is registered If the header field being registered requires its own IANA registry, than the appropriate registry MUST be properly defined. For the feedback type registry, the following MUST be provided in an RFC publication (or Internet draft with IETF consensus or IESG approval) in order to register a new header field name: 1. Name of the feedback type being registered 2. Short description 3. The RFC number (or Internet draft name) in which this feedback type is registered 8.1 Initial Values for the Header Names Registry The data below is populated from this document. The RFC number used for registration of these values is this document. Field Name: Authentication-Results Description: results of authentication check Multiple Appearances: Yes Related "Feedback-Type": any Field Name: Feedback-Type Description: type of feedback report Multiple Appearances: No Related "Feedback-Type": N/A Field Name: Original-Mail-From Description: email address used in the MAIL FROM portion of the original SMTP transaction Multiple Appearances: No Related "Feedback-Type": any Field Name: Original-Rcpt-To Description: copy of the email address used in the RCPT TO portion of the original SMTP transaction Multiple Appearances: No Related "Feedback-Type": any Field Name: Received-Date Shafranovich Expires November 14, 2005 [Page 9] Internet-Draft Format for Feedback Reports May 2005 Description: date the original message was received Multiple Appearances: No Related "Feedback-Type": any Field Name: Reported-Domain Description: relevant domain name Multiple Appearances: Yes Related "Feedback-Type": any Field Name: Reported-URI Description: relevant URI Multiple Appearances: Yes Related "Feedback-Type": any Field Name: Removal-Recipient Description: email address to be removed from the mailing list Multiple Appearances: Yes Related "Feedback-Type": opt-out, opt-out-list Field Name: Source-IP Description: IPv4 or IPv6 address from which the original message was received Multiple Appearances: No Related "Feedback-Type": any Field Name: User-Agent Description: name and version of the program used Multiple Appearances: No Related "Feedback-Type": any Field Name: Version Description: version of specification used Multiple Appearances: No Related "Feedback-Type": any 8.2 Initial values for the "Feedback-Type" registry The initial names and descriptions are provided below. The RFC number used for registration of these values is this document. o abuse - spam or some other kind of email abuse o fraud - indicates some kind of fraud or phishing activity. o opt-out - a request to opt out from ALL mailing lists from this provider. Shafranovich Expires November 14, 2005 [Page 10] Internet-Draft Format for Feedback Reports May 2005 o opt-out-list - a request to opt out from THIS mailing list ONLY. o other - any other feedback that doesn't fit into other types. o virus - report of a virus found in the originating message 9. Security Considerations See section 3 of RFC 3462 [1] 10. Acknowledgments The author would like to thank many of the members of the email community who provided helpful comments and suggestions for this document including many of the participants in ASRG, IETF and MAAWG activities, and all of the members of the abuse-feedback-report public mailing list. 11. References 11.1 Normative References [1] Vaudreuil, G., "The Multipart/Report Content Type for the Reporting of Mail System Administrative Messages", RFC 3462, January 2003. [2] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [3] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types", RFC 2046, November 1996. [4] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999. [5] Klensin, J., "Simple Mail Transfer Protocol", RFC 2821, April 2001. [6] Resnick, P., "Internet Message Format", RFC 2822, April 2001. [7] Hinden, R. and S. Deering, "IP Version 6 Addressing Architecture", RFC 2373, July 1998. [8] Kucherawy, M., "Message Header for Indicating Sender Authentication Status", draft-kucherawy-sender-auth-header-02 Shafranovich Expires November 14, 2005 [Page 11] Internet-Draft Format for Feedback Reports May 2005 (work in progress), May 2005. [9] Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, November 1987. [10] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 2434, October 1998. 11.2 Informative References [11] Freed, N., Klensin, J., and J. Postel, "Multipurpose Internet Mail Extensions (MIME) Part Four: Registration Procedures", BCP 13, RFC 2048, November 1996. [12] Crissman, G., "Proposed Spam Reporting BCP Document", May 2005, . [13] Anti-Spam Research Group (ASRG) of the Internet Research Task Force (IRTF), "Abuse Reporting Standards Subgroup of the ASRG", May 2005, . [14] Crocker, D., "Standard for the format of ARPA Internet text messages", STD 11, RFC 822, August 1982. [15] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifiers (URI): Generic Syntax", RFC 2396, August 1998. Author's Address Yakov Shafranovich SolidMatrix Technologies, Inc. Email: ietf@shaftek.org URI: http://www.shaftek.org Appendix A. Appendix A - Sample Feedback Reports A.1 Simple Report for Email Abuse without Optional Headers Shafranovich Expires November 14, 2005 [Page 12] Internet-Draft Format for Feedback Reports May 2005 From: Date: Thu, 8 Mar 2005 17:40:36 EDT Subject: FW: Earn money To: MIME-Version: 1.0 Content-Type: multipart/report; report-type=feedback-report; boundary="part1_13d.2e68ed54_boundary" --part1_13d.2e68ed54_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit This is an email abuse report for an email message received from IP 10.67.41.167 on Thu, 8 Mar 2005 14:00:00 EDT. For more information about this format please see http://www.mipassoc.org/arf/. --part1_13d.2e68ed54_boundary Content-Type: message/feedback-report Feedback-Type: abuse User-Agent: SomeGenerator/1.0 Version: 0.1 --part1_13d.2e68ed54_boundary Content-Type: message/rfc822 Content-Disposition: inline From: Received: from mailserver.example.net (mailserver.example.net [10.67.41.167]) by example.com with ESMTP id M63d4137594e46; Thu, 08 Mar 2005 14:00:00 -0400 To: Subject: Earn money MIME-Version: 1.0 Content-type: text/plain Message-ID: 8787KJKJ3K4J3K4J3K4J3.mail@example.net Date: Thu, 02 Sep 2004 12:31:03 -0500 Spam Spam Spam Spam Spam Spam Spam Spam Spam Spam Spam Spam --part1_13d.2e68ed54_boundary-- A.2 Opt-Out Report without Message Body Shafranovich Expires November 14, 2005 [Page 13] Internet-Draft Format for Feedback Reports May 2005 From: Date: Thu, 8 Mar 2005 17:40:36 EDT Subject: FW: Earn money To: MIME-Version: 1.0 Content-Type: multipart/report; report-type=feedback-report; boundary="part1_13d.2e68ed54_boundary" --part1_13d.2e68ed54_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit This is an opt-out report for an email message received from IP 10.67.41.167 on Thu, 8 Mar 2005 14:00:00 EDT. For more information about this format please see http://www.mipassoc.org/arf/. --part1_13d.2e68ed54_boundary Content-Type: message/feedback-report Feedback-Type: opt-out User-Agent: SomeGenerator/1.0 Version: 0.1 Removal-Recipient: user@example.com --part1_13d.2e68ed54_boundary Content-Type: message/rfc822-headers Content-Disposition: inline From: Received: from mailserver.example.net (mailserver.example.net [10.67.41.167]) by example.com with ESMTP id M63d4137594e46; Thu, 08 Mar 2005 14:00:00 -0400 To: Subject: Earn money MIME-Version: 1.0 Content-type: text/plain Message-ID: 8787KJKJ3K4J3K4J3K4J3.mail@example.net Date: Thu, 02 Sep 2004 12:31:03 -0500 --part1_13d.2e68ed54_boundary-- A.3 Full Report for Email Abuse with All Headers From: Date: Thu, 8 Mar 2005 17:40:36 EDT Subject: FW: Earn money To: MIME-Version: 1.0 Content-Type: multipart/report; report-type=feedback-report; boundary="part1_13d.2e68ed54_boundary" Shafranovich Expires November 14, 2005 [Page 14] Internet-Draft Format for Feedback Reports May 2005 --part1_13d.2e68ed54_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit This is an email abuse report for an email message received from IP 10.67.41.167 on Thu, 8 Mar 2005 14:00:00 EDT. For more information about this format please see http://www.mipassoc.org/arf/. --part1_13d.2e68ed54_boundary Content-Type: message/feedback-report Feedback-Type: abuse User-Agent: SomeGenerator/1.0 Version: 0.1 Original-Mail-From: Original-Rcpt-To: Received-Date: Thu, 8 Mar 2005 14:00:00 EDT Source-IP: 10.67.41.167 Authentication-Results: mail.example.com smtp.mail=somespammer@example.com; spf=fail Reported-Domain: example.net Reported-Uri: http://example.net/earn_money.html Reported-Uri: mailto:user@example.com Removal-Recipient: user@example.com --part1_13d.2e68ed54_boundary Content-Type: message/rfc822 Content-Disposition: inline From: Received: from mailserver.example.net (mailserver.example.net [10.67.41.167]) by example.com with ESMTP id M63d4137594e46; Thu, 08 Mar 2005 14:00:00 -0400 To: Subject: Earn money MIME-Version: 1.0 Content-type: text/plain Message-ID: 8787KJKJ3K4J3K4J3K4J3.mail@example.net Date: Thu, 02 Sep 2004 12:31:03 -0500 Spam Spam Spam Spam Spam Spam Spam Spam Spam Spam Spam Spam --part1_13d.2e68ed54_boundary-- Shafranovich Expires November 14, 2005 [Page 15] Internet-Draft Format for Feedback Reports May 2005 Appendix B. Status of This Document [To Be Removed Upon Publication] B.1 Discussion Venue Discussion about this document should be directed to the ABUSE- FEEDBACK-REPORT mailing list which is also reachable via . Of course, comments directly to the author are always welcome (you can send them via email to ). B.2 Document Repository and Public Website Copies of this and earlier versions including multiple formats can be found at . A public website regarding this draft and related efforts is located at . B.3 Document History Changes from draft-shafranovich-feedback-report-01-pre1 to draft-shafranovich-feedback-report-01: o Added an "Outstanding Issues" section. o Minor spelling mistakes and clarifications. o Added links to previous work and more examples. o Added three new types: "fraud" for phishing, "opt-out-list" for a single list opt out, and "other" as a catch-all. Changes from draft-shafranovich-feedback-report-00 to draft-shafranovich-feedback-report-01-pre1: o Changed the introduction section to clarify specific points that are out of scope for this document o Added pointers to a public mailing list for discussion and public web page o Clarified the intent section and added some extra points to it o Added a reference to RFC 2119 and changed the document to comply o Made it clear that the requirements section) is not the one defining the standard Shafranovich Expires November 14, 2005 [Page 16] Internet-Draft Format for Feedback Reports May 2005 o Clarified the main format section to make all three parts mandatory o Changed section 4f regarding subject lines to mandate that subject lines should be left intact. Removed the convention for subject lines that was defined in the previous version o Added text to the the machine readable section clarifying its intent. Also added RFC 2119 references, reorganized fields, indicated whether specific header fields can appear more than once and provided references as to how they should be formatted. o Removed "Original-Message-ID", "Authenticated-Domain:" and "Authenticated-Domain-Method" from the draft including related IANA registries. Added "Version", "User-Agent", Original-Mail- From", "Original-Rcpt-To", "Reported-Uri", "Reported-Domain" and "Authentication-Results". o Example has been updated to reflect new headers. o Added a new section on extensibility and changed the IANA section to reflect that. Changes from draft-shafranovich-abuse-report-00 to draft-shafranovich-feedback-report-00: o Name of the format and report changed to 'feedback-report' o Minor spelling corrections o Added authentication headers and registry o Added feedback-type header and registry. B.4 Outstanding Issues Here is a list of some outstanding issues for this document that have not been finalized: o Whether encoding of the machine readable part should be limited to 7-bit o Whether there is a need for both "opt-out" and "opt-out-list", and whether this format should be used for opt-outs at all. o Whether the "from" address should be required to be a human just like other RFCs in the "message/report" family. Shafranovich Expires November 14, 2005 [Page 17] Internet-Draft Format for Feedback Reports May 2005 o Whether there is a need for a new header to indicate munging of the included email message. o Whether different type of convention should be allowed for subject lines. o Whether there should be different types defined for "Reported-Uri" to better indicate to the report receiver how they are related to the email message in question. Shafranovich Expires November 14, 2005 [Page 18] Internet-Draft Format for Feedback Reports May 2005 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Copyright Statement Copyright (C) The Internet Society (2005). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Shafranovich Expires November 14, 2005 [Page 19]