For example:
rdf:Property a rdfs:Class ;
rdfs:isDefinedBy <http://www.w3.org/1999/02/22-rdf-syntax-ns#> ;
rdfs:label "Property" ;
rdfs:comment "The class of RDF properties." ;
rdfs:subClassOf rdfs:Resource .
From: https://www.w3.org/1999/02/22-rdf-syntax-ns
The rdf:Property is referring to several things in the rdfs vocabulary, such as rdfs:Class, despite rdf coming to existence earlier (1996?) than rdfs (1998?).