mime type naming conventions for applications

[John Luke]

Hello all,

	Sorry if I missed this somewhere but, is there a naming recommendation
for application specific mime types? Specifically if you have two mime
types for an app, or only one.  It might be nice to have a small mention
of it somewhere, if only for uniformity.

For example:
application/x-<extension>
or
application/x-<application>-<type>

I would slightly prefer the second one, as it lets you be a little more
flexible with multiple extensions per mime-type, etc.

Thanks