What META.yml syntax does CPAN support?

Does CPAN support and make use of the things you can include in v1.3 
(current) of the META spec?

http://module-build.sourceforge.net/META-spec-v1.3.html

Specifically, does it do anything useful when it comes across 
'recommends' syntax like:

recommends:
     Data::Dumper: 0
     File::Find: 1.03

More importantly, does it do anything useful when it comes across the 
alternate 'optional_features' syntax like:

optional_features:
   - foo:
       description: Provides the ability to blah.
       requires:
         Data::Dumper: 0
         File::Find: 1.03
   - bar:
       description: This feature is not available on this platform.
       excludes_os: MSWin32


Is there some document that describes CPAN behaviour with META.yml files?