Embedding RDF metadata within an XML document

[Warren Hedley <w.hedley@auckland.ac.nz>]

Hi folks,

We are developing an XML-based langauge for defining the structure
of mathematical models of biological systems called CellML. We want to
use RDF for metadata in CellML documents, but are not 100% sure about
the correct way to do so. We want to get this right, to make it feasible
for RDF-savvy search engines, etc. to make use of our metadata even if they
have no knowledge of CellML.

Here are our specific questions:

1. Is it OK to leave off the <rdf:RDF> element and simply
use the <rdf:Description> element as the container for
a block of metadata?

2. If we are embedding the metadata inside the resource to
which it refers, is it appropriate to omit the @about attribute
on the <rdf:Description> element?
Does omitting the @about attribute imply that the RDF block
refers to the resource in which it is contained? (This is the
behaviour that we are after.)

Here is what we think our metadata block will look like (where
"cmeta" is the prefix for our RDF schema's namespace):

<cellml:some_cellml_element>

  <rdf:Description>
    <cmeta:some_metadata_element>
      Some metadata content
    </cmeta:some_metadata_element>
  </rdf:Description>

  Some CellML content

</cellml:some_cellml_element>

<cellml:another_cellml_element>

  <rdf:Description>
    <cmeta:some_metadata_element>
      Different metadata content
    </cmeta:some_metadata_element>
  </rdf:Description>

  Some CellML content

</cellml:another_cellml_element>

Is this correct use of RDF? Are processors likely to be able to
make use of it? Are processors going to be able to determine
which metadata applies to <some_cellml_element> and which
applies to <another_cellml_element>?

Thanks in advance for any help.

-- 
Warren Hedley
Department of Engineering Science
Auckland University
New Zealand