(registered 2026-06-23, last updated 2026-06-23)

Media type name: application

Media subtype name: vnd.softpres-ipf-disk-image

Required parameters: N/A

Optional parameters: N/A

Encoding considerations: binary

Security considerations: IPF (Interchangeable Preservation Format) disk images can store the same data as real floppy disks. That means they may contain arbitrary content, including but not limited to active content. Thus if the users do not trust the contents of the disk image, they should carefully check the contents first before using it (e.g. with a suitable anti-virus software to check for known malicious software). The IPF format also does not provide privacy or full integrity protection, so if these protections are desired they must be applied externally.

Interoperability considerations: There has never been an official documentation of the IPF disk image file format, so this could lead to incompatibilities. But there is a support library available (http://www.kryoflux.com/download/spsdeclib_5.1_source.zip) and the layout has been analysed and documented by a third party, so that applications that follow these sources should be interoperable.

Published specification: 

Third party specification:

https://www.kryoflux.com/download/ipf_documentation_v1.6.pdf

Applications which use this media: The IPF file format is used by floppy disk preservation tools and various emulators of old computers that used such floppy disks.

Fragment identifier considerations: N/A

Restrictions on usage: N/A

Additional information:

1. Deprecated alias names for this type: N/A
2. Magic number(s): 0x43 0x41 0x50 0x53 at file offset 0 (i.e. the ASCII letters "CAPS")
3. File extension(s): .ipf
4. Macintosh file type code: N/A
5. Object Identifiers: N/A

Person to contact for further information:

1. Name: Thomas Huth
2. Email: huth&tuxfamily.org

Intended usage: COMMON

IPF files are usually created by disk preservation tools like the software for the "KryoFlux" floppy controller card. The IPF files contain the low-level flux data of the disk and thus can be used to fully preserve the contents of a floppy disk. These files then can be used in emulators for providing the floppy disk contents to the emulated system.

Author/Change controller: Thomas Huth, on behalf of the Software Preservation Society