please confirm acceptable mime types for standalone mathml

Hello,

I gather from rfc3023 that the registered media type for standalone  
MathML2 documents is application/mathml+xml. Is that correct? Could  
you also confirm whether other media types are acceptable for this  
document type?

I'm trying to make sure that the Markup validator[1], which can  
validate MathML, has its facts straight.

[1] http://validator.w3.org/

Thank you.
-- 
olivier