&...; in RDF/XML — is this a standard RDF prefix expression?
rdf, rdfs, wordnet, xml
Solution
`&wn20schema;` is an entity reference.
The XML document should contain or point to its expansion, i.e., something like
<!ENTITY wn20schema "…">
`&wn20schema;` will be replaced with `…`.
References:
- XML 1.0: http://www.w3.org/TR/2008/REC-xml-20081126/#sec-physical-struct
- See also examples.
- XML 1.1: http://www.w3.org/TR/2006/REC-xml11-20060816/#sec-physical-struct
- See also examples.
Problem
I downloaded WordNet2.0 fullset. In the RDF/XML document, wnfull.rdfs, there are elements like this the following that use, e.g., `&wn20schema;AdverbSynset` as attribute values (in places where URIs would be expected). I know how `#`, `url/` and `value:` are commonly used, but what is this `&...;` notation? ``` <rdfs:Class rdf:about="&wn20schema;Synset" /> <rdfs:Class rdf:about="&wn20schema;AdjectiveSynset" /> <rdfs:Class rdf:about="&wn20schema;AdjectiveSatelliteSynset" /> <rdfs:Class rdf:about="&wn20schema;AdverbSynset" /> ```