IANA Mime Types list is missing some key ones

[martindholmes]

The latest version of the mime types document here:

https://www.iana.org/assignments/media-types/media-types.xml

Does not list e.g. image/jpeg or image/gif, so our diagnostics flag these as wrong. It's not clear to me whether the omission is erroneous or not, but either way, it appears that we can no longer trust that document to provide a reliable list of mime types for checking purposes. We should revisit this in a week or two to see if it was an error that got corrected (the current version is only a few days old).

[Hibrix-net]

I'm having the exact same doubt as you do.

[martindholmes]

Sorry that this got dropped; I'll take another look as soon as I get the chance.

[intranetlabs]

Has anyone learned anything interesting since coming across this issue?

[andersk]

The entry in the IANA “image” table with “jpeg” in the first column is the listing for image/jpeg. Its registration predates the IANA media type registry and is listed by reference to the RFC that standardized it, which is why the second column is blank. There are 18 types registered in this way:

• image/gif
• image/ief
• image/jpeg
• image/x-emf (deprecated)
• image/x-wmf (deprecated)
• message/external-body
• message/partial
• message/rfc822
• model/mesh
• model/vrml
• multipart/alternative
• multipart/digest
• multipart/mixed
• multipart/parallel
• text/enriched
• text/plain
• text/richtext
• video/mpeg

They are no less official than the others and should be included.

Edit: I raised this issue of potential confusion with IANA and they are in the process of more fully addressing it, but meanwhile they’ve added this note at the top:

Note: Some early registrations have no registration template. The absence of a template does not imply a different or reduced registration status.

Edit 2: IANA has fixed the table presentation to be less confusing by linking these historical types to a message instead of leaving the second column blank.