A net search suggests that text/x-lilypond is correct, and text/lilypond, without the “x-" experimental prefix, is acceptable; “text“ indicates it is human-readable, so “application” should not be used.
> On 9 Jun 2026, at 15:09, Massimo Capozza <[email protected]> wrote: > > Hello Hans, > > Please note that the deprecations you mentioned only apply to Javascript. > Furthermore, the x-prefix should be still used with Lilypond because the > relevant MIME type it is not registered with the Internet Assigned Numbers > Authority (IANA), so it must be still considered as experimental. > > As I mentioned in a previous email, we already have these MIME declarations > in .htaccess: > > AddType application/x-nwc nwc > AddType application/x-sibelius-score sib sco > AddType application/octet-stream cap capx > > Normally, these declarations should directly open the file in the application > associated to the relevant file extension, which the user can freely select > on his/her computer. So, in the case of Lilypond, one may select Frescobaldi, > a text editor (e.g., Notepad++ that will immediately detect the UTF-8 > encoding), or whatever else. If no application is associated, the file is > downloaded "as is". This behaviour is in use since many years, and nobody > complained about it, so I think that it would be fine for Lilypond, too, > without introducing inconsistencies with other music file formats. > > These are the reasons why I proposed to use "application/x-lilypond". > "text/x-lilypond" would also work, but just because the Lilypond files are > text files, it would not work for the other music file types. > > Kind Regards. > > Max > > >> >>> On 8 Jun 2026, at 14:30, Gabriel Ellsworth <[email protected]> >>> wrote: >>> >>> Apologies for the double email, but I just figured out how to view the >>> response headers >>> >> To inspect the HTTP headers in browsers, like Firefox, load the page, then >> choose Inspect, say from a pop-up menu, click Network, and reload. >> >> One can set the “content-type” on the server by: >> AddCharset UTF-8 .ly >> AddType text/lilypond .ly >> following (with some changes): >> https://silvain-dupertuis.org/test/lilypond/displaying-text-files.html >> >> The “text/lilypond” alternative forms “text/x-lilypond”, >> “application/lilypond” or “application/x-lilypond“ have been deprecated or >> are experimental, and should not be used. See: >> https://stackoverflow.com/questions/9664282/difference-between-application-x-javascript-and-text-javascript-content-types >> >> >> >
