From RFC 2302 To: ietf-types@iana.org Subject: Registration of Standard MIME media type image/tiff MIME media type name: image MIME subtype name: tiff Required parameters: none Optional parameters: application There is no format specified for the value of this parameter in addition to that specified by [MIME1]. Various applications of TIFF may define values as required. New values should be defined in standards track RFCs and the values should be registered with IANA, using the registration form included in Appendix A. There is no default value for application, as the absence of the application parameter indicates that the encoded TIFF image is Baseline TIFF or that it is not necessary to identify the application. It is up to the implementation to determine the application (if necessary) and render the image to the user. Encoding considerations: Binary or Base-64 generally preferred Security considerations: TIFF utilizes a structure which can store image data and attributes of this image data. The fields defined in the TIFF specification are of a descriptive nature and provide information that is useful to facilitate viewing and rendering of images by a recipient. As such, the fields currently defined in the TIFF specification do not in themselves create additional security risks, since the fields are not used to induce any particular behavior by the recipient application. TIFF has an extensible structure, so that it is theoretically possible that fields could be defined in the future which could be used to induce particular actions on the part of the recipient, thus presenting additional security risks, but this type of capability is not supported in the referenced TIFF specification. Indeed, the definition of fields which would include such processing instructions is inconsistent with the goals and spirit of the TIFF specification. Interoperability considerations: The ability of implementations to handle all the defined applications (or profiles within applications) of TIFF may not be ubiquitous. As a result, implementations may decode and attempt to display the encoded TIFF image data only to determine that the image cannot be rendered. The presence of the application parameter may aid in allowing this determination before dispatching for rendering. However, it should be noted that the parameter value is not intended to convey levels of capabilities for a particular application. Published specification: TIFF (Tag Image File Format) is defined in: TIFF (TM) Revision 6.0 - Final - June 3, 1992 Adobe Developers Association Adobe Systems Incorporated 345 Park Avenue San Jose, CA 95110-2704 Phone: +1-408-536-6000 Fax: +1-408-537-6000 A copy of this specification can be found in: ftp://ftp.adobe.com/pub/adobe/devrelations/devtechnotes/pdff iles/tiff6.pdf Applications which use this media type: Imaging, fax, messaging and multi-media Additional information: Magic number(s): II (little-endian): 49 49 42 00 hex MM (big-endian): 4D 4D 00 42 hex File extension(s): .TIF Macintosh File Type Code(s): TIFF Person & email address to contact for further information: Glenn W. Parsons Glenn.Parsons@Nortel.ca James Rafferty Jrafferty@worldnet.att.net Stephen Zilles szilles@adobe.com Intended usage: COMMON Change controller: Stephen Zilles IANA Registration for image/tiff Application Parameter Values used for facsimile (From RFC 2301) To: IANA@isi.edu Subject: Registration of new Application parameter values for image/tiff MIME media type name: image/tiff Optional parameters: Application New Value(s): faxbw, faxcolor Description of Use: faxbw - The "faxbw" application parameter is suitable for use by applications that can process one or more TIFF for facsimile profiles or subsets used for the encoding of black-and-white facsimile data. The definition of the use of this value is contained in Section 9 of this document (TIFFPLUS). Faxcolor - The "faxcolor" application parameter is suitable for use by applications that can process one or more TIFF for facsimile profiles or subsets that can be used for the encoding of black and white, AND color facsimile data. The definition of the use of this value is contained in Section 9 of this document (TIFFPLUS). Security Considerations: Security considerations related to use of the TIFF subsets described by the "faxbw" and "faxcolor" values of the Application parameter are identified in Section 10 of this document (TIFFPLUS). Persons & email addresses to contact for further information: Glenn W. Parsons (Glenn.Parsons@Nortel.ca) James Rafferty (Jrafferty@worldnet.att.net) Stephen Zilles (szilles@adobe.com) Change Controller: Stephen Zilles INFORMATION TO THE SUBMITTER: The accepted registrations will be listed in the "Assigned Numbers" series of RFCs. The information in the registration form is freely distributable.