MIME

End-to-end cryptographic protections for email messages can provide useful security. However, the standards for providing cryptographic protection are extremely flexible. That flexibility can trap users and cause surprising failures. This document offers guidance for Mail User Agent (MUA) implementers to help mitigate those risks and to make end-to-end email simple and secure for the end user. It provides a useful set of vocabulary as well as recommendations to avoid common failures. It also identifies a number of currently unsolved usability and interoperability problems.

S/MIME version 3.1 introduced a mechanism to provide end-to-end cryptographic protection of email message headers. However, few implementations generate messages using this mechanism, and several legacy implementations have revealed rendering or security issues when handling such a message.

This document updates the S/MIME specification (RFC 8551) to offer a different mechanism that provides the same cryptographic protections but with fewer downsides when handled by legacy clients. Furthermore, it offers more explicit usability, privacy, and security guidance for clients when generating or handling email messages with cryptographic protection of message headers.

The Header Protection scheme defined here is also applicable to messages with PGP/MIME (Pretty Good Privacy with MIME) cryptographic protections.

The S/MIME development community benefits from sharing samples of signed or encrypted data. This document facilitates such collaboration by defining a small set of X.509v3 certificates and keys for use when generating such samples.

This document specifies an extension to "The JSON Meta Application Protocol (JMAP) for Mail" (RFC 8621) for returning the S/MIME signature verification status.

The popularity of social media has led to user comfort with easily signaling basic reactions to an author's posting, such as with a 'thumbs up' or 'smiley' graphic. This specification permits a similar facility for Internet Mail.

This document specifies identifiers and challenges required to enable the Automated Certificate Management Environment (ACME) to issue certificates for use by email users that want to use S/MIME.

The United States Government has published the National Security Agency (NSA) Commercial National Security Algorithm (CNSA) Suite, which defines cryptographic algorithm policy for national security applications. This document specifies the conventions for using the United States National Security Agency's CNSA Suite algorithms in Secure/Multipurpose Internet Mail Extensions (S/MIME) as specified in RFC 8551. It applies to the capabilities, configuration, and operation of all components of US National Security Systems that employ S/MIME messaging. US National Security Systems are described in NIST Special Publication 800-59. It is also appropriate for all other US Government systems that process high-value information. It is made publicly available for use by developers and operators of these and any other system deployments.

This document specifies conventions for X.509 certificate usage by Secure/Multipurpose Internet Mail Extensions (S/MIME) v4.0 agents. S/MIME provides a method to send and receive secure MIME messages, and certificates are an integral part of S/MIME agent processing. S/MIME agents validate certificates as described in RFC 5280 ("Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile"). S/MIME agents must meet the certificate-processing requirements in this document as well as those in RFC 5280. This document obsoletes RFC 5750.

This document defines Secure/Multipurpose Internet Mail Extensions (S/MIME) version 4.0. S/MIME provides a consistent way to send and receive secure MIME data. Digital signatures provide authentication, message integrity, and non-repudiation with proof of origin. Encryption provides data confidentiality. Compression can be used to reduce data size. This document obsoletes RFC 5751.

Mobile messaging applications used with the Session Initiation Protocol (SIP) commonly use some combination of the SIP MESSAGE method and the Message Session Relay Protocol (MSRP). While these provide mechanisms for hop-by-hop security, neither natively provides end-to-end protection. This document offers guidance on how to provide end-to-end authentication, integrity protection, and confidentiality using the Secure/Multipurpose Internet Mail Extensions (S/MIME). It updates and provides clarifications for RFCs 3261, 3428, and 4975.

This document defines the 'multipart/multilingual' content type, which is an addition to the Multipurpose Internet Mail Extensions (MIME) standard. This content type makes it possible to send one message that contains multiple language versions of the same information. The translations would be identified by a language tag and selected by the email client based on a user's language settings.

This document describes how to use secure DNS to associate an S/MIME user's certificate with the intended domain name, similar to the way that DNS-Based Authentication of Named Entities (DANE), RFC 6698, does for TLS.

This document describes a procedure for when a Military Message Handling System (MMHS) message is composed by one user and is only released to the mail transfer system when one or more Authorizing Users authorize release of the message by adding the MMHS-Authorizing-Users header field. The resulting message can be optionally signed by the sender and/or reviewer, allowing recipients to verify both the original signature (if any) and the review signatures.

A common format simplifies exchange of secondary school academic transcripts via electronic mail. Existing standards are applied to prevent unauthorized alteration of transcript content and to deliver transcripts directly and securely from each student to his or her chosen recipients. By eliminating third-party intervention and surveillance, the defined protocol better protects student privacy and independence than does current practice.

This document describes how the S/MIME protocol can be extended in order to secure message header fields defined in RFC 5322. This technology provides security services such as data integrity, non-repudiation, and confidentiality. This extension is referred to as 'Secure Headers'.

RFC 7001 specifies the Authentication-Results header field for conveying results of message authentication checks. This document defines a new authentication method to be used in the Authentication- Results header field for S/MIME-related signature checks.

Many Internet applications have a need for object-based security mechanisms in addition to security mechanisms at the network layer or transport layer. For many years, the Cryptographic Message Syntax (CMS) has provided a binary secure object format based on ASN.1. Over time, binary object encodings such as ASN.1 have become less common than text-based encodings, such as the JavaScript Object Notation (JSON). This document defines a set of use cases and requirements for a secure object format encoded using JSON, drawn from a variety of application security mechanisms currently in development.

Secure/Multipurpose Internet Mail Extensions (S/MIME) defined the Content-Type parameter "smime-type". As the list of defined values for that parameter has increased, it has become clear that a registry is needed to document these values. This document creates the registry, registers the current values, and specifies the policies for registration of new values.

When the S/MIME Mail Security Working Group was chartered, an object identifier arc was donated by RSA Data Security for use by that working group. This document describes the object identifiers that were assigned in that donated arc, transfers control of that arc to IANA, and establishes IANA allocation policies for any future assignments within that arc.

This document defines a set of Secure/Multipurpose Internet Mail Extensions (S/MIME) Capability types for ASN.1 encoding for the current set of public keys defined by the PKIX working group. This facilitates the ability for a requester to specify information on the public keys and signature algorithms to be used in responses. "Online Certificate Status Protocol Algorithm Agility" (RFC 6277) details an example of where this is used. This document is not an Internet Standards Track specification; it is published for informational purposes.

This document specifies the conventions for using the United States National Security Agency's Suite B algorithms in Secure/Multipurpose Internet Mail Extensions (S/MIME) as specified in RFC 5751. This document obsoletes RFC 5008. This document is not an Internet Standards Track specification; it is published for informational purposes.

New hash algorithms are being developed that may include parameters. Cryptographic Message Syntax (CMS) has not currently defined any hash algorithms with parameters, but anecdotal evidence suggests that defining one could cause major problems. This document defines just such an algorithm and describes how to use it so that experiments can be run to find out how bad including hash parameters will be. This document defines an Experimental Protocol for the Internet community.

The Cryptographic Message Syntax (CMS), unlike X.509/PKIX certificates, is vulnerable to algorithm substitution attacks. In an algorithm substitution attack, the attacker changes either the algorithm being used or the parameters of the algorithm in order to change the result of a signature verification process. In X.509 certificates, the signature algorithm is protected because it is duplicated in the TBSCertificate.signature field with the proviso that the validator is to compare both fields as part of the signature validation process. This document defines a new attribute that contains a copy of the relevant algorithm identifiers so that they are protected by the signature or authentication process. [STANDARDS-TRACK]

Since 1997, the Italian laws have recognized electronic delivery systems as legally usable. In 2005, after two years of technical tests, the characteristics of an official electronic delivery service, named certified electronic mail (in Italian "Posta Elettronica Certificata") were defined, giving the system legal standing.

The design of the entire system was carried out by the National Center for Informatics in the Public Administration of Italy (DigitPA), followed by efforts for the implementation and testing of the service. The DigitPA has given the Italian National Research Council (CNR), and in particular the Institute of Information Science and Technologies at the CNR (ISTI), the task of running tests on providers of the service to guarantee the correct implementation and interoperability. This document describes the certified email system adopted in Italy. It represents the system as it is at the moment of writing, following the technical regulations that were written based upon the Italian Law DPR. November 2, 2005. This document is not an Internet Standards Track specification; it is published for informational purposes.

This memo defines an extension to the SMTP service whereby an SMTP content body consisting of text containing octets outside of the US-ASCII octet range (hex 00-7F) may be relayed using SMTP. [STANDARDS-TRACK]

Abstract Syntax Notation One (ASN.1) is widely used throughout the IETF Security Area and has been for many years. Some specifications were written using a now deprecated version of ASN.1 and some were written using the current version of ASN.1. Not all ASN.1 compilers support both older and current syntax. This document is intended to provide guidance to specification authors and to implementers converting ASN.1 modules from one version of ASN.1 to another version without causing changes to the "bits on the wire". This document does not provide a comprehensive tutorial of any version of ASN.1. Instead, it addresses ASN.1 features that are used in IETF Security Area specifications with a focus on items that vary with the ASN.1 version. This document is not an Internet Standards Track specification; it is published for informational purposes.

The Cryptographic Message Syntax (CMS) format, and many associated formats, are expressed using ASN.1. The current ASN.1 modules conform to the 1988 version of ASN.1. This document updates those ASN.1 modules to conform to the 2002 version of ASN.1. There are no bits-on-the-wire changes to any of the formats; this is simply a change to the syntax. This document is not an Internet Standards Track specification; it is published for informational purposes.

The Public Key Infrastructure using X.509 (PKIX) certificate format, and many associated formats, are expressed using ASN.1. The current ASN.1 modules conform to the 1988 version of ASN.1. This document updates those ASN.1 modules to conform to the 2002 version of ASN.1. There are no bits-on-the-wire changes to any of the formats; this is simply a change to the syntax. This document is not an Internet Standards Track specification; it is published for informational purposes.

The caller preferences specification for the Session Initiation Protocol (SIP) allows a caller to express preferences that the call be routed to a User Agent (UA) with particular capabilities. Similarly, a specification exists to allow a UA to indicate its capabilities in a registration. Amongst those capabilities are the type of media streams the agent supports, described as top-level MIME types. The 'application' MIME type is used to describe a broad range of stream types, and it provides insufficient granularity as a capability. This specification allows a UA to indicate which application subtypes the agent supports. [STANDARDS-TRACK]

This document describes the RTP payload format of a mU-law EMbedded Coder for Low-delay IP communication (UEMCLIP), an enhanced speech codec of ITU-T G.711. The bitstream has a scalable structure with an embedded u-law bitstream, also known as PCMU, thus providing a handy transcoding operation between narrowband and wideband speech. [STANDARDS-TRACK]

This document defines extensions to the Sieve email filtering language to permit analysis and manipulation of the MIME body parts of an email message. [STANDARDS-TRACK]

This document specifies how message bodies are handled in SIP. Additionally, this document specifies SIP user agent support for MIME (Multipurpose Internet Mail Extensions) in message bodies. [STANDARDS-TRACK]

Over its thirty-five-year history, Internet Mail has changed significantly in scale and complexity, as it has become a global infrastructure service. These changes have been evolutionary, rather than revolutionary, reflecting a strong desire to preserve both its installed base and its usefulness. To collaborate productively on this large and complex system, all participants need to work from a common view of it and use a common language to describe its components and the interactions among them. But the many differences in perspective currently make it difficult to know exactly what another participant means. To serve as the necessary common frame of reference, this document describes the enhanced Internet Mail architecture, reflecting the current service. This memo provides information for the Internet community.

Email has become a popular distribution service for a variety of socially unacceptable, mass-effect purposes. The most obvious ones include spam and worms. This note recommends conventions for the operation of email submission and transport services between independent operators, such as enterprises and Internet Service Providers. Its goal is to improve lines of accountability for controlling abusive uses of the Internet mail service. To this end, this document offers recommendations for constructive operational policies between independent operators of email submission and transmission services.

Email authentication technologies are aimed at providing assurances and traceability between internetworked networks. In many email services, the weakest link in the chain of assurances is initial submission of a message. This document offers recommendations for constructive operational policies for this first step of email sending, the submission (or posting) of email into the transmission network. Relaying and delivery entail policies that occur subsequent to submission and are outside the scope of this document. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.

This document defines the MIME sub-type audio/t38. The usage of this MIME type, which is intended for use within Session Description Protocol (SDP), is specified within ITU-T Recommendation T.38. This memo defines a Historic Document for the Internet community.

In conversational video applications, far-end camera control protocol is used by participants to control the remote camera. The protocol that is commonly used is ITU H.281 over H.224. The document registers the H224 media type. It defines the syntax and the semantics of the Session Description Protocol (SDP) parameters needed to support far-end camera control protocol using H.224. [STANDARDS-TRACK]

This document defines an extension to the URL MIME External-Body Access-Type to satisfy the content indirection requirements for the Session Initiation Protocol (SIP). These extensions are aimed at allowing any MIME part in a SIP message to be referred to indirectly via a URI. [STANDARDS-TRACK]

This document describes the conventions for using the cryptographic algorithms GOST 28147-89, GOST R 34.10-94, GOST R 34.10-2001, and GOST R 34.11-94 with the Cryptographic Message Syntax (CMS). The CMS is used for digital signature, digest, authentication, and encryption of arbitrary message contents. [STANDARDS-TRACK]

This document serves to register and document the standard MIME types associated with the 3GPP2 multimedia file format, which is part of the family based on the ISO Media File Format. [STANDARDS-TRACK]

This document defines the standard MIME types associated with MP4 files. It also recommends use of registered MIME types according to the type of contents. [STANDARDS-TRACK]

Implementation of generators and parsers of header fields requires certain information about those fields. Interoperability is most likely when all such information is explicitly provided by the technical specification of the fields. Lacking such explicit information, implementers may guess, and interoperability may suffer. This memo identifies information useful to implementers of header field generators and parsers. This memo provides information for the Internet community.

This document defines a certificate extension for inclusion of Secure/Multipurpose Internet Mail Extensions (S/MIME) Capabilities in X.509 public key certificates, as defined by RFC 3280. This certificate extension provides an optional method to indicate the cryptographic capabilities of an entity as a complement to the S/MIME Capabilities signed attribute in S/MIME messages according to RFC 3851. [STANDARDS-TRACK]

This document specifies IANA registration procedures for MIME external body access types and content-transfer-encodings. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.

A message originator sometimes sends content in a form the recipient cannot process or would prefer not to process a form of lower quality than is preferred. Such content needs to be converted to an acceptable form, with the same information or constrained information (e.g., changing from color to black and white). In a store-and-forward environment, it may be convenient to have this conversion performed by an intermediary. This specification integrates two ESMTP extensions and three MIME content header fields, which defines a cooperative service that permits authorized, accountable content form conversion by intermediaries. [STANDARDS-TRACK]

This RFC documents the format used for Comma-Separated Values (CSV) files and registers the associated MIME type "text/csv". This memo provides information for the Internet community.

This document gives examples of message bodies formatted using S/MIME. Specifically, it has examples of Cryptographic Message Syntax (CMS) objects and S/MIME messages (including the MIME formatting). It includes examples of many common CMS formats. The purpose of this document is to help increase interoperability for S/MIME and other protocols that rely on CMS. This memo provides information for the Internet community.

This document provides an applicability statement (RFC 2026, Section 3.2) that describes how to exchange structured business data securely using the HTTP transfer protocol, instead of SMTP; the applicability statement for SMTP is found in RFC 3335. Structured business data may be XML; Electronic Data Interchange (EDI) in either the American National Standards Committee (ANSI) X12 format or the UN Electronic Data Interchange for Administration, Commerce, and Transport (UN/EDIFACT) format; or other structured data formats. The data is packaged using standard MIME structures. Authentication and data confidentiality are obtained by using Cryptographic Message Syntax with S/MIME security body parts. Authenticated acknowledgements make use of multipart/signed Message Disposition Notification (MDN) responses to the original HTTP message. This applicability statement is informally referred to as "AS2" because it is the second applicability statement, produced after "AS1", RFC 3335. [STANDARDS-TRACK]

This document defines the text/red MIME sub-type. "Red" is short for redundant. The actual RTP packetization for this MIME type is specified in RFC 2198. [STANDARDS-TRACK]

This document describes the registration of the Multipurpose Internet Mail Extensions (MIME) sub-types to be used by the international astronomical community for the interchange of Flexible Image Transport System (FITS) files. The encoding is defined by the published FITS standard documents. The FITS format has been in use since 1979, and almost all data from astronomical observations are interchanged by using FITS. This memo provides information for the Internet community.

This document defines the initial IANA registration for permanent mail and MIME message header fields, per RFC 3864. [STANDARDS-TRACK]

This document specifies the conventions for using the SEED encryption algorithm for encryption with the Cryptographic Message Syntax (CMS).

SEED is added to the set of optional symmetric encryption algorithms in CMS by providing two classes of unique object identifiers (OIDs). One OID class defines the content encryption algorithms and the other defines the key encryption algorithms. [STANDARDS-TRACK]

This document is a revised version of RFC 2301. The revisions, summarized in the list attached as Annex B, are based on discussions and suggestions for improvements that have been made since RFC 2301 was issued in March 1998, and on the results of independent implementations and interoperability testing.

This RFC 2301 revision describes the Tag Image File Format (TIFF) representation of image data specified by the International Telecommunication Union (ITU-T) Recommendations for black-and-white and color facsimile. This file format specification is commonly known as TIFF for Fax eXtended (TIFF-FX). It formally defines minimal, extended, and lossless Joint Bi-level Image experts Group (JBIG) profiles (Profiles S, F, J) for black-and-white fax and base JPEG, lossless JBIG, and Mixed Raster Content profiles (Profiles C, L, M) for color and grayscale fax. These profiles correspond to the content of the applicable ITU-T Recommendations. [STANDARDS-TRACK]

This document describes the registration of the MIME sub-type image/tiff-fx. The encodings are defined by File Format for Internet Fax and its extensions. [STANDARDS-TRACK]

This document describes a protocol for adding cryptographic signature and encryption services to X.400 content with Secure/Multipurpose Internet Mail Extensions (S/MIME). [STANDARDS-TRACK]

This document describes protocol options for conveying objects that have been protected using the Cryptographic Message Syntax (CMS) and Secure/Multipurpose Internet Mail Extensions (S/MIME) version 3.1 over an X.400 message transfer system. [STANDARDS-TRACK]

RFC 3261 currently specifies 3DES as the mandatory-to-implement ciphersuite for implementations of S/MIME in the Session Initiation Protocol (SIP). This document updates the normative guidance of RFC 3261 to require the Advanced Encryption Standard (AES) for S/MIME. [STANDARDS-TRACK]

This document serves to register and document the standard MIME types associated with the 3GPP multimedia file format, which is part of the family based on the ISO Media File Format. [STANDARDS-TRACK]

This document specifies a restricted profile of the Internet multimedia messaging protocols for use between voice processing server platforms. The profile is referred to as the Voice Profile for Internet Mail (VPIM) in this document. These platforms have historically been special-purpose computers and often do not have the same facilities normally associated with a traditional Internet Email-capable computer. As a result, VPIM also specifies additional functionality, as it is needed. This profile is intended to specify the minimum common set of features to allow interworking between conforming systems. This document obsoletes RFC 2421 and describes version 2 of the profile with greater precision. No protocol changes were made in this revision. A list of changes from RFC 2421 are noted in Appendix F. Appendix A summarizes the protocol profiles of this version of VPIM. [STANDARDS-TRACK]

This document describes the registration of the MIME sub-type audio/32KADPCM Adaptive Differential Pulse Code Modulation for toll quality audio. This audio encoding is defined by the ITU-T in Recommendation G.726. [STANDARDS-TRACK]

This document describes the MIME header Content-Duration that is intended for use with any time varying media content (typically audio/* or video/*). [STANDARDS-TRACK]

This document serves to register and document the standard MIME types associated with the ISO/IEC 15444 standards, commonly known as JPEG 2000 (Joint Photographic Experts Group). [STANDARDS-TRACK]

This document describes the use of a mechanism for identifying body parts that a sender deems critical in a multi-part Internet mail message. The mechanism described is a parameter to Content-Disposition, as described by RFC 3204. By knowing what parts of a message the sender deems critical, a content gateway can intelligently handle multi-part messages when providing gateway services to systems of lesser capability. Critical content can help a content gateway to decide what parts to forward. It can indicate how hard a gateway should try to deliver a body part. It can help the gateway to pick body parts that are safe to silently delete when a system of lesser capability receives a message. In addition, critical content can help the gateway chose the notification strategy for the receiving system. Likewise, if the sender expects the destination to do some processing on a body part, critical content allows the sender to mark body parts that the receiver must process. [STANDARDS-TRACK]

This memo defines a Multipurpose Internet Mail Extensions (MIME) content-type that may be used by a message transfer agent (MTA) or electronic mail gateway to report the result of an attempt to deliver a message to one or more recipients. This content-type is intended as a machine-processable replacement for the various types of delivery status notifications currently used in Internet electronic mail. Because many messages are sent between the Internet and other messaging systems (such as X.400 or the so-called "Local Area Network (LAN)-based" systems), the Delivery Status Notification (DSN) protocol is designed to be useful in a multi-protocol messaging environment. To this end, the protocol described in this memo provides for the carriage of "foreign" addresses and error codes, in addition to those normally used in Internet mail. Additional attributes may also be defined to support "tunneling" of foreign notifications through Internet mail. [STANDARDS-TRACK]

This document describes the registration of the MIME sub-type

image/tiff. The baseline encoding of TIFF (Tag Image File Format) is

defined by [TIFF]. This document refines an earlier sub-type

registration in RFC 1528 [TPC.INT].

This document describes how to exchange structured business data

securely using SMTP transport for Electronic Data Interchange,

(EDI - either the American Standards Committee X12 or UN/EDIFACT,

Electronic Data Interchange for Administration, Commerce and

Transport), XML or other data used for business to business data

interchange. The data is packaged using standard MIME

content-types. Authentication and privacy are obtained by using

Cryptographic Message Syntax (S/MIME) or OpenPGP security body

parts. Authenticated acknowledgements make use of

multipart/signed replies to the original SMTP message.

This document describes the registration of the MIME sub-type

image/t38. The encoding is defined by [T.38] and is intended

for use as an SDP media descriptor.

This document defines a "Content-language:" header, for use in cases where one desires to indicate the language of something that has RFC 822-like headers, like MIME body parts or Web documents, and an "Accept-Language:" header for use in cases where one wishes to indicate one's preferences with regard to language. [STANDARDS-TRACK]

This document discusses how company security policy for data classification can be mapped to the S/MIME security label. Actual policies from three companies provide worked examples. This memo provides information for the Internet community.

This document describes the registration of the MIME sub-type application/dicom (Digital Imaging and Communications in Medicine). The baseline encoding is defined by the DICOM Standards Committee in "Digital Imaging and Communications in Medicine". This memo provides information for the Internet community.

This document describes how the S/MIME (Secure/Multipurpose Internet Mail Extensions) protocol can be processed and generated by a number of components of a communication system, such as message transfer agents, guards and gateways to deliver security services. These services are collectively referred to as 'Domain Security Services'. This memo defines an Experimental Protocol for the Internet community.

This document describes how the OpenPGP Message Format can be used to provide privacy and authentication using the Multipurpose Internet Mail Extensions (MIME) security content types described in RFC 1847. [STANDARDS-TRACK]

This document describes the registration of the Multipurpose Internet Mail Extensions (MIME) sub-type application/font-tdpfr. The encoding is defined by the PFR Specification. This memo provides information for the Internet community.

This memo specifies how to incorporate International Data Encryption Algorithm (IDEA) into CMS or S/MIME as an additional strong algorithm for symmetric encryption. This memo provides information for the Internet community.

This memo defines two extensions to the SMTP (Simple Mail Transfer Protocol) service. [STANDARDS-TRACK]

The intention of this document, in conjunction with RFC 2958, is to enable MIME-enabled mail software, and other systems using Internet media types, to carry out Whois++ transactions. This memo provides information for the Internet community.

The intention of this document, in conjunction with RFC 2957, is to enable MIME-enabled mail software, and other systems using Internet media types, to carry out Whois++ transactions. This memo provides information for the Internet community.

Multipurpose Internet Mail Extensions (MIME) and various other Internet protocols are capable of using many different charsets. This in turn means that the ability to label different charsets is essential. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.

This memo defines a Multipurpose Internet Mail Extensions (MIME) ' Content-features:' header that can be used to annotate a MIME message part using this expression format, and indicates some ways it might be used. [STANDARDS-TRACK]

This memo defines a media feature tag whose value is a Multipurpose Internet Mail Extensions (MIME) content type. [STANDARDS-TRACK]

This document defines a multipurpose internet mail extensions (MIME) directory profile for holding a lightweight directory access protocol (LDAP) schema. This memo provides information for the Internet community.

Entities composing web pages to provide services over the Hypertext Transfer Protocol (HTTP) frequently have the problem of not knowing what Multipurpose Internet Mail Extensions (MIME) types have handlers installed at a user's browser. This document summarizes reasonable techniques to solve this problem for most of the browsers actually deployed on the Internet as of early 2000. This memo provides information for the Internet community.

This document will describe the situations relevant to implementations of S/MIME version 3 in which protection is necessary and the methods that can be used to prevent these attacks. This memo provides information for the Internet community.

This document defines an abstract model for a presence and instant messaging system. It defines the various entities involved, defines terminology, and outlines the services provided by the system. This memo provides information for the Internet community.

This document defines a minimal set of requirements that IMPP must meet. This memo provides information for the Internet community.

This document describes the definitions of those objects as well as the methods and requirements needed to define a new index type. [STANDARDS-TRACK]

This document describes four optional security service extensions for S/MIME. [STANDARDS-TRACK]

This document defines the audio/L16 MIME type, a reasonable quality audio format for use in Internet applications. This memo provides information for the Internet community.

This document a) defines the use of a MIME multipart/related structure to aggregate a text/html root resource and the subsidiary resources it references, and b) specifies a MIME content-header (Content-Location) that allow URIs in a multipart/related text/html root body part to reference subsidiary resources in other body parts of the same multipart/related structure. [STANDARDS-TRACK]

This memorandum describes a set of MIME types for use with the ISO Interlibrary Loan Protocol (ISO 10160/10161). This memo provides information for the Internet community.

This document examines the problems associated with use of MIME security multiparts and gateways to non-MIME environments. [STANDARDS-TRACK]

This document defines the Multipart/Related content-type and provides examples of its use. [STANDARDS-TRACK]

The Uniform Resource Locator (URL) schemes, "cid:" and "mid:" allow references to messages and the body parts of messages. For example, within a single multipart message, one HTML body part might include embedded references to other parts of the same message. [STANDARDS-TRACK]

Certain text formats, for example Postscript (MIME-Type: application/postscript; file extension .ps) and Portable Document Format (MIME-Type: application/pdf; file extension .pdf) specify exactly the page layout of the printed document. The commonly used paper format is different in North America and the rest of the world. North America uses the 'Letter' format, while the rest of the world mostly uses the ISO-standard 'A4' format. This means that documents formatted on one continent may not be easily printable on another continent. This memo gives advice on how to produce documents which are equally well printable with the Letter and the A4 formats. This memo provides information for the Internet community. It does not specify an Internet standard of any kind.

This document describes a protocol for adding cryptographic signature and encryption services to MIME data. This memo provides information for the Internet community. It does not specify an Internet standard of any kind.

This memo describes the mechanisms S/MIME uses to create and validate keys using certificates. This memo provides information for the Internet community. It does not specify an Internet standard of any kind.

This document relates primarily to the ITU-T 1988 and 1992 X.400 Series Recommendations / ISO IEC 10021 International Standard. This ISO/ITU-T standard is referred to in this document as "X.400", which is a convenient shorthand. [STANDARDS-TRACK]

This document defines how to map body parts of X.400 messages into MIME entities and vice versa, including the handling of multipart messages and forwarded messages. [STANDARDS-TRACK]

This document contains the definitions, originally contained in RFC 1494, on how to carry CCITT G3Fax in MIME, and how to translate it to its X.400 representation. [STANDARDS-TRACK]

This document describes methods for carrying PostScript information in the two standard mail systems MIME and X.400, and the conversion between them. [STANDARDS-TRACK]

This document contains the definitions, originally contained in RFC 1495 and RFC 1341, on how to carry ODA in MIME, and how to translate it to its X.400 representation. This memo defines an Experimental Protocol for the Internet community.

The standard referred shortly into this document as "X.400" relates to the ISO/IEC 10021 - CCITT 1984, 1988 and 1992 X.400 Series Recommendations covering the Message Oriented Text Interchange Service (MOTIS). This document covers the Inter Personal Messaging System (IPMS) only. This memo defines an Experimental Protocol for the Internet community.

This memo is the complete technical specification to store in the Internet Domain Name System (DNS) the mapping information (MCGAM) needed by MIXER conformant e-mail gateways and other tools to map RFC822 domain names into X.400 O/R names and vice versa. [STANDARDS-TRACK]

This specification defines how to represent and maintain these mappings (MIXER Conformant Global Address Mappings of MCGAMs) in an X.500 or LDAP directory. [STANDARDS-TRACK]

This memo defines extensions to the RFC 2045 media type and RFC 2183 disposition parameter value mechanisms. This memo also defines an extension to the encoded words defined in RFC 2047 to allow the specification of the language to be used for display as well as the character set. [STANDARDS-TRACK]

This memorandum provides a mechanism for representing objects which are files of Machine-Readable Cataloging records (MARC). The MARC formats are standards for the representation and communication of bibliographic and related information. A MARC record contains metadata for an information resource following MARC format specifications. This memo provides information for the Internet community. It does not specify an Internet standard of any kind.

This memo provides a mechanism whereby messages conforming to the MIME specifications [RFC 2045, RFC 2046, RFC 2047, RFC 2048, RFC 2049] can convey presentational information. It specifies the "Content- Disposition" header field, which is optional and valid for any MIME entity ("message" or "body part"). [STANDARDS-TRACK]

The purpose of this memo is to propose an update to Internet RFC 2045 to include a new primary content-type to be known as "model". [STANDARDS-TRACK]

This initial document specifies the various headers used to describe the structure of MIME messages. [STANDARDS-TRACK]

This particular document is the third document in the series. It describes extensions to RFC 822 to allow non-US-ASCII text data in Internet mail header fields. [STANDARDS-TRACK]

This set of documents, collectively called the Multipurpose Internet Mail Extensions, or MIME, redefines the format of messages. This fifth and final document describes MIME conformance criteria as well as providing some illustrative examples of MIME message formats, acknowledgements, and the bibliography. [STANDARDS-TRACK]

This document describes how Pretty Good Privacy (PGP) can be used to provide privacy and authentication using the Multipurpose Internet Mail Extensions (MIME) security content types described in RFC1847. [STANDARDS-TRACK]

This memo defines a new access-type for message/external-body MIME parts for Uniform Resource Locators (URLs). [STANDARDS-TRACK]

This document describes a standard encoding for electronic mail [RFC822] containing Greek text and provides implementation guide-lines. This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind.

This memorandum provides guidelines for using the United States Department of Defense Military Standard MIL-STD-1840, "Automated Interchange of Technical Information," with the Internet electronic mail standards, RFC 822 and RFC 1521. This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind.

This document defines one particular type of MIME data, the text/enriched MIME type. This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind.