我下载了完整的WordNet2.0。在 RDF/XML 文档 wnfull.rdfs 中,有像下面这样的元素,例如,&wn20schema;AdverbSynset用作属性值(在需要 URI 的地方)。我知道#,url/和value:是常用的,但是这个&...;符号是什么?
<rdfs:Class rdf:about="&wn20schema;Synset" />
<rdfs:Class rdf:about="&wn20schema;AdjectiveSynset" />
<rdfs:Class rdf:about="&wn20schema;AdjectiveSatelliteSynset" />
<rdfs:Class rdf:about="&wn20schema;AdverbSynset" />