Semantic Web tutorial - Comparing document formats

Not application-specific
Several candidate DTDs/Schemas.
Sometimes a reasonable choice

<!DOCTYPE Graph [
 <!ENTITY rdf    "http://www.w3.org/1999/02/22-rdf-syntax-ns#">
 <!ENTITY bio    "http://www.w3.org/2000/10/swap/test/demo1/biology#">
 <!ENTITY ns1    "http://www.w3.org/2000/10/swap/test/demo1/about-pat#">
 <!ENTITY per    "http://www.w3.org/2000/10/swap/test/demo1/friends-vocab#">
]>
<Graph>
  <Triple>
    <subject><uri>&ns1;pat</uri></subject>
    <predicate><uri>&rdf;type</uri></predicate>
    <object><uri>&bio;Human</uri></object>
  </Triple>
  <Triple>
    <subject><uri>&ns1;pat</uri></subject>
    <predicate><uri>&per;name</uri></predicate>
    <object><literal>Pat Smith</literal></object>
  </Triple>
  <Triple>
    <subject><uri>&ns1;pat</uri></subject>
    <predicate><uri>&per;pet</uri></predicate>
    <object><nodeID>genid1</nodeID></object>
  </Triple>
  <Triple>
    <subject><nodeID>genid1</nodeID></subject>
    <predicate><uri>&rdf;type</uri></predicate>
    <object><uri>&bio;Dog</uri></object>
  </Triple>
  <Triple>
    <subject><nodeID>genid1</nodeID></subject>
    <predicate><uri>&per;name</uri></predicate>
    <object><literal>Rover</literal></object>
  </Triple>
</Graph>

XML Triples