| draft-ietf-httpbis-p6-cache-02.txt |  | draft-ietf-httpbis-p6-cache-03.txt |
--- | --- | --- | --- | ---
| Network Working Group R. Fielding, Ed. |  | Network Working Group R. Fielding, Ed. |
| Internet-Draft Day Software |  | Internet-Draft Day Software |
| Obsoletes: 2616 (if approved) J. Gettys |  | Obsoletes: 2616 (if approved) J. Gettys |
| Intended status: Standards Track One Laptop per Child |  | Intended status: Standards Track One Laptop per Child |
| Expires: August 27, 2008 J. Mogul |  | Expires: December 19, 2008 J. Mogul |
| HP |  | HP |
| H. Frystyk |  | H. Frystyk |
| Microsoft |  | Microsoft |
| L. Masinter |  | L. Masinter |
| Adobe Systems |  | Adobe Systems |
| P. Leach |  | P. Leach |
| Microsoft |  | Microsoft |
| T. Berners-Lee |  | T. Berners-Lee |
| W3C/MIT |  | W3C/MIT |
| Y. Lafon, Ed. |  | Y. Lafon, Ed. |
| W3C |  | W3C |
| J. Reschke, Ed. |  | J. Reschke, Ed. |
| greenbytes |  | greenbytes |
| February 24, 2008 |  | June 17, 2008 |
| HTTP/1.1, part 6: Caching |  | HTTP/1.1, part 6: Caching |
| draft-ietf-httpbis-p6-cache-02 |  | draft-ietf-httpbis-p6-cache-03 |
| Status of this Memo |  | Status of this Memo |
| By submitting this Internet-Draft, each author represents that any |  | By submitting this Internet-Draft, each author represents that any |
| applicable patent or other IPR claims of which he or she is aware |  | 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 |  | 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. |  | aware will be disclosed, in accordance with Section 6 of BCP 79. |
| Internet-Drafts are working documents of the Internet Engineering |  | Internet-Drafts are working documents of the Internet Engineering |
| Task Force (IETF), its areas, and its working groups. Note that |  | Task Force (IETF), its areas, and its working groups. Note that |
| skipping to change at page 1, line 49 |  | skipping to change at page 1, line 49 |
| and may be updated, replaced, or obsoleted by other documents at any |  | and may be updated, replaced, or obsoleted by other documents at any |
| time. It is inappropriate to use Internet-Drafts as reference |  | time. It is inappropriate to use Internet-Drafts as reference |
| material or to cite them other than as "work in progress." |  | material or to cite them other than as "work in progress." |
| The list of current Internet-Drafts can be accessed at |  | The list of current Internet-Drafts can be accessed at |
| http://www.ietf.org/ietf/1id-abstracts.txt. |  | http://www.ietf.org/ietf/1id-abstracts.txt. |
| The list of Internet-Draft Shadow Directories can be accessed at |  | The list of Internet-Draft Shadow Directories can be accessed at |
| http://www.ietf.org/shadow.html. |  | http://www.ietf.org/shadow.html. |
| This Internet-Draft will expire on August 27, 2008. |  | This Internet-Draft will expire on December 19, 2008. |
| Copyright Notice |  |  |
| Copyright (C) The IETF Trust (2008). |  |  |
| Abstract |  | Abstract |
| The Hypertext Transfer Protocol (HTTP) is an application-level |  | The Hypertext Transfer Protocol (HTTP) is an application-level |
| protocol for distributed, collaborative, hypermedia information |  | protocol for distributed, collaborative, hypermedia information |
| systems. HTTP has been in use by the World Wide Web global |  | systems. HTTP has been in use by the World Wide Web global |
| information initiative since 1990. This document is Part 6 of the |  | information initiative since 1990. This document is Part 6 of the |
| seven-part specification that defines the protocol referred to as |  | seven-part specification that defines the protocol referred to as |
| "HTTP/1.1" and, taken together, obsoletes RFC 2616. Part 6 defines |  | "HTTP/1.1" and, taken together, obsoletes RFC 2616. Part 6 defines |
| requirements on HTTP caches and the associated header fields that |  | requirements on HTTP caches and the associated header fields that |
| control cache behavior or indicate cacheable response messages. |  | control cache behavior or indicate cacheable response messages. |
| Editorial Note (To be removed by RFC Editor) |  | Editorial Note (To be removed by RFC Editor) |
| Discussion of this draft should take place on the HTTPBIS working |  | Discussion of this draft should take place on the HTTPBIS working |
| group mailing list (ietf-http-wg@w3.org). The current issues list is |  | group mailing list (ietf-http-wg@w3.org). The current issues list is |
| at <http://www.tools.ietf.org/wg/httpbis/trac/report/11> and related |  | at <http://www.tools.ietf.org/wg/httpbis/trac/report/11> and related |
| documents (including fancy diffs) can be found at |  | documents (including fancy diffs) can be found at |
| <http://www.tools.ietf.org/wg/httpbis/>. |  | <http://www.tools.ietf.org/wg/httpbis/>. |
| This draft incorporates those issue resolutions that were either |  | The changes in this draft are summarized in Appendix B.4. |
| collected in the original RFC2616 errata list |  |  |
| (<http://purl.org/NET/http-errata>), or which were agreed upon on the |  |  |
| mailing list between October 2006 and November 2007 (as published in |  |  |
| "draft-lafon-rfc2616bis-03"). |  |  |
| Table of Contents |  | Table of Contents |
| 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 |  | 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 |
| 1.1. Purpose . . . . . . . . . . . . . . . . . . . . . . . . . 5 |  | 1.1. Purpose . . . . . . . . . . . . . . . . . . . . . . . . . 5 |
| 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 6 |  | 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 6 |
| 1.3. Requirements . . . . . . . . . . . . . . . . . . . . . . . 7 |  | 1.3. Requirements . . . . . . . . . . . . . . . . . . . . . . . 7 |
| 2. Notational Conventions and Generic Grammar . . . . . . . . . . 8 |  | 2. Notational Conventions and Generic Grammar . . . . . . . . . . 8 |
| 3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 |  | 3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 |
| 3.1. Cache Correctness . . . . . . . . . . . . . . . . . . . . 8 |  | 3.1. Cache Correctness . . . . . . . . . . . . . . . . . . . . 8 |
| skipping to change at page 4, line 5 |  | skipping to change at page 4, line 5 |
| 16.2.2. What May be Stored by Caches . . . . . . . . . . . . 30 |  | 16.2.2. What May be Stored by Caches . . . . . . . . . . . . 30 |
| 16.2.3. Modifications of the Basic Expiration Mechanism . . . 31 |  | 16.2.3. Modifications of the Basic Expiration Mechanism . . . 31 |
| 16.2.4. Cache Revalidation and Reload Controls . . . . . . . 33 |  | 16.2.4. Cache Revalidation and Reload Controls . . . . . . . 33 |
| 16.2.5. No-Transform Directive . . . . . . . . . . . . . . . 35 |  | 16.2.5. No-Transform Directive . . . . . . . . . . . . . . . 35 |
| 16.2.6. Cache Control Extensions . . . . . . . . . . . . . . 36 |  | 16.2.6. Cache Control Extensions . . . . . . . . . . . . . . 36 |
| 16.3. Expires . . . . . . . . . . . . . . . . . . . . . . . . . 37 |  | 16.3. Expires . . . . . . . . . . . . . . . . . . . . . . . . . 37 |
| 16.4. Pragma . . . . . . . . . . . . . . . . . . . . . . . . . . 38 |  | 16.4. Pragma . . . . . . . . . . . . . . . . . . . . . . . . . . 38 |
| 16.5. Vary . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 |  | 16.5. Vary . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 |
| 16.6. Warning . . . . . . . . . . . . . . . . . . . . . . . . . 39 |  | 16.6. Warning . . . . . . . . . . . . . . . . . . . . . . . . . 39 |
| 17. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 42 |  | 17. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 42 |
|  |  | 17.1. Message Header Registration . . . . . . . . . . . . . . . 42 |
| 18. Security Considerations . . . . . . . . . . . . . . . . . . . 42 |  | 18. Security Considerations . . . . . . . . . . . . . . . . . . . 42 |
| 19. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 42 |  | 19. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 43 |
| 20. References . . . . . . . . . . . . . . . . . . . . . . . . . . 42 |  | 20. References . . . . . . . . . . . . . . . . . . . . . . . . . . 43 |
| 20.1. Normative References . . . . . . . . . . . . . . . . . . . 42 |  | 20.1. Normative References . . . . . . . . . . . . . . . . . . . 43 |
| 20.2. Informative References . . . . . . . . . . . . . . . . . . 44 |  | 20.2. Informative References . . . . . . . . . . . . . . . . . . 44 |
| Appendix A. Compatibility with Previous Versions . . . . . . . . 44 |  | Appendix A. Compatibility with Previous Versions . . . . . . . . 44 |
| A.1. Changes from RFC 2068 . . . . . . . . . . . . . . . . . . 44 |  | A.1. Changes from RFC 2068 . . . . . . . . . . . . . . . . . . 44 |
| A.2. Changes from RFC 2616 . . . . . . . . . . . . . . . . . . 44 |  | A.2. Changes from RFC 2616 . . . . . . . . . . . . . . . . . . 45 |
| Appendix B. Change Log (to be removed by RFC Editor before |  | Appendix B. Change Log (to be removed by RFC Editor before |
| publication) . . . . . . . . . . . . . . . . . . . . 44 |  | publication) . . . . . . . . . . . . . . . . . . . . 45 |
| B.1. Since RFC2616 . . . . . . . . . . . . . . . . . . . . . . 45 |  | B.1. Since RFC2616 . . . . . . . . . . . . . . . . . . . . . . 45 |
| B.2. Since draft-ietf-httpbis-p6-cache-00 . . . . . . . . . . . 45 |  | B.2. Since draft-ietf-httpbis-p6-cache-00 . . . . . . . . . . . 45 |
| B.3. Since draft-ietf-httpbis-p6-cache-01 . . . . . . . . . . . 45 |  | B.3. Since draft-ietf-httpbis-p6-cache-01 . . . . . . . . . . . 46 |
|  |  | B.4. Since draft-ietf-httpbis-p6-cache-02 . . . . . . . . . . . 46 |
| Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 |  | Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 |
| Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 48 |  | Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 49 |
| Intellectual Property and Copyright Statements . . . . . . . . . . 51 |  | Intellectual Property and Copyright Statements . . . . . . . . . . 52 |
| 1. Introduction |  | 1. Introduction |
| HTTP is typically used for distributed information systems, where |  | HTTP is typically used for distributed information systems, where |
| performance can be improved by the use of response caches, and |  | performance can be improved by the use of response caches, and |
| includes a number of elements intended to make caching work as well |  | includes a number of elements intended to make caching work as well |
| as possible. Because these elements interact with each other, it is |  | as possible. Because these elements interact with each other, it is |
| useful to describe the caching design of HTTP separately. This |  | useful to describe the caching design of HTTP separately. This |
| document defines aspects of HTTP/1.1 related to caching and reusing |  | document defines aspects of HTTP/1.1 related to caching and reusing |
| response messages. |  | response messages. |
| skipping to change at page 42, line 25 |  | skipping to change at page 42, line 25 |
| If an implementation receives a message with a warning-value that |  | If an implementation receives a message with a warning-value that |
| includes a warn-date, and that warn-date is different from the Date |  | includes a warn-date, and that warn-date is different from the Date |
| value in the response, then that warning-value MUST be deleted from |  | value in the response, then that warning-value MUST be deleted from |
| the message before storing, forwarding, or using it. (This prevents |  | the message before storing, forwarding, or using it. (This prevents |
| bad consequences of naive caching of Warning header fields.) If all |  | bad consequences of naive caching of Warning header fields.) If all |
| of the warning-values are deleted for this reason, the Warning header |  | of the warning-values are deleted for this reason, the Warning header |
| MUST be deleted as well. |  | MUST be deleted as well. |
| 17. IANA Considerations |  | 17. IANA Considerations |
| [[anchor1: TBD.]] |  | 17.1. Message Header Registration |
|  |  | The Message Header Registry located at <http://www.iana.org/ |
|  |  | assignments/message-headers/message-header-index.html> should be |
|  |  | updated with the permanent registrations below (see [RFC3864]): |
|  |  | +-------------------+----------+----------+--------------+ |
|  |  | | Header Field Name | Protocol | Status | Reference | |
|  |  | +-------------------+----------+----------+--------------+ |
|  |  | | Age | http | standard | Section 16.1 | |
|  |  | | Cache-Control | http | standard | Section 16.2 | |
|  |  | | Expires | http | standard | Section 16.3 | |
|  |  | | Pragma | http | standard | Section 16.4 | |
|  |  | | Vary | http | standard | Section 16.5 | |
|  |  | | Warning | http | standard | Section 16.6 | |
|  |  | +-------------------+----------+----------+--------------+ |
|  |  | The change controller is: "IETF (iesg@ietf.org) - Internet |
|  |  | Engineering Task Force". |
| 18. Security Considerations |  | 18. Security Considerations |
| Caching proxies provide additional potential vulnerabilities, since |  | Caching proxies provide additional potential vulnerabilities, since |
| the contents of the cache represent an attractive target for |  | the contents of the cache represent an attractive target for |
| malicious exploitation. Because cache contents persist after an HTTP |  | malicious exploitation. Because cache contents persist after an HTTP |
| request is complete, an attack on the cache can reveal information |  | request is complete, an attack on the cache can reveal information |
| long after a user believes that the information has been removed from |  | long after a user believes that the information has been removed from |
| the network. Therefore, cache contents should be protected as |  | the network. Therefore, cache contents should be protected as |
| sensitive information. |  | sensitive information. |
| skipping to change at page 43, line 11 |  | skipping to change at page 43, line 27 |
| [ISO-8859-1] |  | [ISO-8859-1] |
| International Organization for Standardization, |  | International Organization for Standardization, |
| "Information technology -- 8-bit single-byte coded graphic |  | "Information technology -- 8-bit single-byte coded graphic |
| character sets -- Part 1: Latin alphabet No. 1", ISO/ |  | character sets -- Part 1: Latin alphabet No. 1", ISO/ |
| IEC 8859-1:1998, 1998. |  | IEC 8859-1:1998, 1998. |
| [Part1] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., |  | [Part1] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., |
| Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., |  | Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., |
| and J. Reschke, Ed., "HTTP/1.1, part 1: URIs, Connections, |  | and J. Reschke, Ed., "HTTP/1.1, part 1: URIs, Connections, |
| and Message Parsing", draft-ietf-httpbis-p1-messaging-02 |  | and Message Parsing", draft-ietf-httpbis-p1-messaging-03 |
| (work in progress), February 2008. |  | (work in progress), June 2008. |
| [Part2] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., |  | [Part2] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., |
| Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., |  | Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., |
| and J. Reschke, Ed., "HTTP/1.1, part 2: Message |  | and J. Reschke, Ed., "HTTP/1.1, part 2: Message |
| Semantics", draft-ietf-httpbis-p2-semantics-02 (work in |  | Semantics", draft-ietf-httpbis-p2-semantics-03 (work in |
| progress), February 2008. |  | progress), June 2008. |
| [Part3] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., |  | [Part3] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., |
| Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., |  | Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., |
| and J. Reschke, Ed., "HTTP/1.1, part 3: Message Payload |  | and J. Reschke, Ed., "HTTP/1.1, part 3: Message Payload |
| and Content Negotiation", draft-ietf-httpbis-p3-payload-02 |  | and Content Negotiation", draft-ietf-httpbis-p3-payload-03 |
| (work in progress), February 2008. |  | (work in progress), June 2008. |
| [Part4] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., |  | [Part4] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., |
| Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., |  | Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., |
| and J. Reschke, Ed., "HTTP/1.1, part 4: Conditional |  | and J. Reschke, Ed., "HTTP/1.1, part 4: Conditional |
| Requests", draft-ietf-httpbis-p4-conditional-02 (work in |  | Requests", draft-ietf-httpbis-p4-conditional-03 (work in |
| progress), February 2008. |  | progress), June 2008. |
| [Part5] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., |  | [Part5] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., |
| Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., |  | Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., |
| and J. Reschke, Ed., "HTTP/1.1, part 5: Range Requests and |  | and J. Reschke, Ed., "HTTP/1.1, part 5: Range Requests and |
| Partial Responses", draft-ietf-httpbis-p5-range-02 (work |  | Partial Responses", draft-ietf-httpbis-p5-range-03 (work |
| in progress), February 2008. |  | in progress), June 2008. |
| [Part7] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., |  | [Part7] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., |
| Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., |  | Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., |
| and J. Reschke, Ed., "HTTP/1.1, part 7: Authentication", |  | and J. Reschke, Ed., "HTTP/1.1, part 7: Authentication", |
| draft-ietf-httpbis-p7-auth-02 (work in progress), |  | draft-ietf-httpbis-p7-auth-03 (work in progress), |
| February 2008. |  | June 2008. |
| [RFC2047] Moore, K., "MIME (Multipurpose Internet Mail Extensions) |  | [RFC2047] Moore, K., "MIME (Multipurpose Internet Mail Extensions) |
| Part Three: Message Header Extensions for Non-ASCII Text", |  | Part Three: Message Header Extensions for Non-ASCII Text", |
| RFC 2047, November 1996. |  | RFC 2047, November 1996. |
| [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, March 1997. |  | Requirement Levels", BCP 14, RFC 2119, March 1997. |
| 20.2. Informative References |  | 20.2. Informative References |
| [RFC1305] Mills, D., "Network Time Protocol (Version 3) |  | [RFC1305] Mills, D., "Network Time Protocol (Version 3) |
| Specification, Implementation", RFC 1305, March 1992. |  | Specification, Implementation", RFC 1305, March 1992. |
| [RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., |  | [RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., |
| Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext |  | Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext |
| Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999. |  | Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999. |
|  |  | [RFC3864] Klyne, G., Nottingham, M., and J. Mogul, "Registration |
|  |  | Procedures for Message Header Fields", BCP 90, RFC 3864, |
|  |  | September 2004. |
| Appendix A. Compatibility with Previous Versions |  | Appendix A. Compatibility with Previous Versions |
| A.1. Changes from RFC 2068 |  | A.1. Changes from RFC 2068 |
| A case was missed in the Cache-Control model of HTTP/1.1; s-maxage |  | A case was missed in the Cache-Control model of HTTP/1.1; s-maxage |
| was introduced to add this missing case. (Sections 6, 16.2, 16.2.3) |  | was introduced to add this missing case. (Sections 6, 16.2, 16.2.3) |
| Transfer-coding and message lengths all interact in ways that |  | Transfer-coding and message lengths all interact in ways that |
| required fixing exactly when chunked encoding is used (to allow for |  | required fixing exactly when chunked encoding is used (to allow for |
| transfer encoding that may not be self delimiting); it was important |  | transfer encoding that may not be self delimiting); it was important |
| skipping to change at page 46, line 4 |  | skipping to change at page 46, line 21 |
| o Use names of RFC4234 core rules DQUOTE and HTAB (work in progress |  | o Use names of RFC4234 core rules DQUOTE and HTAB (work in progress |
| on <http://www3.tools.ietf.org/wg/httpbis/trac/ticket/36>) |  | on <http://www3.tools.ietf.org/wg/httpbis/trac/ticket/36>) |
| B.3. Since draft-ietf-httpbis-p6-cache-01 |  | B.3. Since draft-ietf-httpbis-p6-cache-01 |
| Closed issues: |  | Closed issues: |
| o <http://www3.tools.ietf.org/wg/httpbis/trac/ticket/82>: "rel_path |  | o <http://www3.tools.ietf.org/wg/httpbis/trac/ticket/82>: "rel_path |
| not used" |  | not used" |
| Other changes: |  | Other changes: |
| o Get rid of duplicate BNF rule names ("host" -> "uri-host") (work |  | o Get rid of duplicate BNF rule names ("host" -> "uri-host") (work |
| in progress on |  | in progress on |
| <http://www3.tools.ietf.org/wg/httpbis/trac/ticket/36>) |  | <http://www3.tools.ietf.org/wg/httpbis/trac/ticket/36>) |
| o Add explicit references to BNF syntax and rules imported from |  | o Add explicit references to BNF syntax and rules imported from |
| other parts of the specification. |  | other parts of the specification. |
|  |  | B.4. Since draft-ietf-httpbis-p6-cache-02 |
|  |  | Ongoing work on IANA Message Header Registration |
|  |  | (<http://www3.tools.ietf.org/wg/httpbis/trac/ticket/40>): |
|  |  | o Reference RFC 3984, and update header registrations for headers |
|  |  | defined in this document. |
| Index |  | Index |
| A |  | A |
| age 7 |  | age 7 |
| Age header 27 |  | Age header 27 |
| C |  | C |
| cache 5 |  | cache 5 |
| Cache Directives |  | Cache Directives |
| max-age 32 |  | max-age 32-33 |
| max-age 33 |  |  |
| max-stale 32 |  | max-stale 32 |
| min-fresh 32 |  | min-fresh 32 |
| must-revalidate 34 |  | must-revalidate 34 |
| no-cache 29 |  | no-cache 29 |
| no-store 30 |  | no-store 30 |
| no-transform 35 |  | no-transform 35 |
| only-if-cached 34 |  | only-if-cached 34 |
| private 29 |  | private 29 |
| proxy-revalidate 35 |  | proxy-revalidate 35 |
| public 29 |  | public 29 |
| skipping to change at page 47, line 34 |  | skipping to change at page 48, line 11 |
| Age 27 |  | Age 27 |
| Cache-Control 27 |  | Cache-Control 27 |
| Expires 37 |  | Expires 37 |
| Pragma 38 |  | Pragma 38 |
| Vary 38 |  | Vary 38 |
| Warning 39 |  | Warning 39 |
| heuristic expiration time 7 |  | heuristic expiration time 7 |
| M |  | M |
| max-age |  | max-age |
| Cache Directive 32 |  | Cache Directive 32-33 |
| Cache Directive 33 |  |  |
| max-stale |  | max-stale |
| Cache Directive 32 |  | Cache Directive 32 |
| min-fresh |  | min-fresh |
| Cache Directive 32 |  | Cache Directive 32 |
| must-revalidate |  | must-revalidate |
| Cache Directive 34 |  | Cache Directive 34 |
| N |  | N |
| no-cache |  | no-cache |
| Cache Directive 29 |  | Cache Directive 29 |
| skipping to change at page 51, line 44 |  | skipping to change at line 2337 |
| attempt made to obtain a general license or permission for the use of |  | attempt made to obtain a general license or permission for the use of |
| such proprietary rights by implementers or users of this |  | such proprietary rights by implementers or users of this |
| specification can be obtained from the IETF on-line IPR repository at |  | specification can be obtained from the IETF on-line IPR repository at |
| http://www.ietf.org/ipr. |  | http://www.ietf.org/ipr. |
| The IETF invites any interested party to bring to its attention any |  | The IETF invites any interested party to bring to its attention any |
| copyrights, patents or patent applications, or other proprietary |  | copyrights, patents or patent applications, or other proprietary |
| rights that may cover technology that may be required to implement |  | rights that may cover technology that may be required to implement |
| this standard. Please address the information to the IETF at |  | this standard. Please address the information to the IETF at |
| ietf-ipr@ietf.org. |  | ietf-ipr@ietf.org. |
| Acknowledgment |  |  |
| Funding for the RFC Editor function is provided by the IETF |  |  |
| Administrative Support Activity (IASA). |  |  |
End of changes. 24 change blocks.
| 38 lines changed or deleted |  | 61 lines changed or added |
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