I don't see the advantage with using XML::Smart either :-)

Ah, I meant XML::Rules :-)

I just tried to convert the sample XML from XML::Rules' SYNOPSIS into a schema:

trang test.xml test.rnc

And the result:

default namespace = ""

start =
  element doc {
    element person {
      element fname { xsd:NMTOKEN },
      element lname { xsd:NMTOKEN },
      element email { xsd:NMTOKEN },
      element address {
        element street { xsd:NMTOKEN },
        element city { xsd:NMTOKEN },
        element country { xsd:NMTOKEN },
        element bogus { xsd:NMTOKEN }
      },
      element phones {
        element phone {
          attribute type { xsd:NCName },
          xsd:NMTOKEN
        }+
      }
    }+
  }

Which looks quite reasonable. trang can also convert into .xsd files, which look uglier but are needed for XML::Compile operation.