Lisa Dusseault wrote:
Hi,
This has come up before and stalled the whole attempt to standardize a PATCH method for HTTP: the lack of a properly registered MIME type for any binary or text diff format.
The GDiff format described in http://www.w3.org/TR/NOTE-gdiff-19970901 states the MIME type but it was never registered. The IPR situation is completely unclear. No author of this has ever responded to my pings.
The VCDIFF format is described in http://www.faqs.org/rfcs/rfc3284.html does not choose a MIME type. The IPR disclosure <https://datatracker.ietf.org/public/ipr_detail_show.cgi?ipr_id=40> states that AT&T grants licenses to "transmit data over the Internet under HTTP 1.1". I do not want to start to interpret whether that covers new HTTP 1.1 methods as well as the ones that existed when this grant was made. An AT&T guy responded to my emails and said he'd suggest a more liberal license to the lawyers but we never saw anything come of that.
Julian recently mentioned the POSIX 'diff' format which is most widely used and probably under the most liberal license due to existing source code licenses. No official MIME type was ever suggested for this until Julian's mail but a bit of googling suggests that some applications informally use application/diff and this is probably what is meant by that. I am unaware of an existing formal spec for this -- and that's the sticking point for registering this one -- although clearly interoperability is common.
Can we just ask IANA to register any or all of these, perhaps with appropriate disclaimers in the form about IPR or specification formality? Surely that would be better than the status quo. Can I help cut red tape here?
I would propose the following: - Write an RFC registering a media type (or media types) for the various output formats of POSIX diff (see previous thread over here). - Define a *very* simply binary patch format, without looking at GDIFF or VCDIFF. I'm ready to work on that. Best regards, Julian