preserve mixed case custom tags?

I have some custom controls in form, <xxx:ServerControl />, which need
to keep their mixed case in Tidy's output.  I can make them recognized
by Tidy if I make them all lowercase with the 'new-empty-tags' option,
but they are then converted to all lowercase in the resulting output
which causes breakage with ASP.NET processing.

 

Is there a way to preserve the mixed case of custom tags?

 

Thanks,

Glenn