No nested <meta> elements?

Hi,

DocBook 5.2* supports the new <meta> element. That's great!

However, as far as I can see, you can either have:

  a) an empty <meta/> element, or
  b) an <meta> element as a parent for other DocBook elements.

It isn't allowed to add a <meta> element inside another <meta>, right? Is there
a specific reason for this? What would your take on allowing nested <meta>s?

Thanks!

--
Gruß/Regards
  Thomas Schraitle