Note which as values are supported for <link rel=preload>

[tunetheweb]

Browsers do not support all as types in <link rel=preload>.

For Chromium see here: https://chromium.googlesource.com/chromium/src.git/+/refs/heads/main/third_party/blink/renderer/core/loader/preload_helper.cc#176

And here:
https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/rel/preload#browser_compatibility

However further testing browsers show ALL BROWSERS all only support a subset of values:
https://resource-loading-examples.glitch.me/preload-types.html

So made this a general comment at the top, rather than a flag for every browser.

[tunetheweb]

Have asked for the HTML spec to be updated: whatwg/html#8332 (comment)

And will also look at updating MDN which is also currently wrong.

[Fyrd]

Thanks!