Tag Image File Format Fax eXtended (TIFF-FX) - image/tiff-fx MIME Sub-type Registration
obsoleted by
- rfc-3950 — Tag Image File Format Fax eXtended (TIFF-FX) - image/tiff-fx MIME Sub-type Registration
Extracted elements (9)
TIFF-FX is built on the existing TIFF structure to enable standardized messaging-based fax over the Internet while maintaining compatibility with ITU-T Group 3 facsimile recommendations, leveraging TIFF's historical use in store-and-forward fax messaging applications.
TIFF-FX recommends a file structure compatible with low-memory and page-level streaming implementations, reflecting the resource-constrained environments typical of fax devices and messaging gateways.
Annex A documents a correction to the TIFF-FX magic numbers: the little-endian value was corrected from 49 49 42 00 hex to 49 49 2A 00 hex, and the big-endian value from 4D 4D 00 42 hex to 4D 4D 00 2A hex (edit dated November 21, 2000).
Implementations may not universally support all TIFF-FX profiles and applications, so a recipient may decode and attempt to display a TIFF-FX image only to find it cannot be rendered due to profile incompatibility.
Binary data in image/tiff-fx MUST use base64 encoding on transports that cannot accommodate binary data directly.
The image/tiff-fx MIME sub-type refers to TIFF-FX Profiles J, C, L, and M encoded image data and any future TIFF-FX extensions, or a subset. The image/tiff-fx content type may also be used for black-and-white data encoded using Profiles S or F.
Registers the MIME sub-type image/tiff-fx for TIFF-FX encoded image data covering Profiles J, C, L, M, S, F, and any future TIFF-FX extensions. The registration is submitted to [email protected] with intended usage COMMON.
The fields defined in the TIFF-FX specification are descriptive and do not induce particular behavior by the recipient application, so they do not in themselves create additional security risks. However, TIFF-FX's extensible structure theoretically allows future fields that could induce recipient actions, though this is inconsistent with the goals of the specification.
TIFF-FX files are identified by magic numbers: little-endian (II) files begin with 49 49 2A 00 hex; big-endian (MM) files begin with 4D 4D 00 2A hex. The file extension is .TFX and the Macintosh File Type Code is TFX.