Can a required argument exist after an optional argument?

[saschanaz]

Long time ago there was this restriction added in 2011:

webidl/Overview.xml

Lines 1391 to 1396 in 3785917

	<p>
	Web IDL operations do not support being called with omitted optional arguments
	unless all subsequent optional arguments are also omitted. Bindings for
	languages that do support function calling in this way will fail such
	calls in a language binding specific manner.
	</p>

This was lifted in 2013 by 97499d4, but I don't think it was well advertised and at least one parser still disallows this: #1211 (comment)

I think we need to double check and add an explicit phrase about whether this is allowed or disallowed.

[domenic]

Thanks for the detective work!

I'm not sure we need an explicit phrase; it seems like we just need to fix buggy parsers. But maybe a note would be helpful, indeed.