http://www.w3.org/2004/02/skos/core#notation
Property notation

DatatypeProperty

http://www.w3.org/2004/02/skos/core

notation

A notation, also known as classification code, is a string of characters such as T58.5 or 303.4833 used to uniquely identify a concept within the scope of a given concept scheme.

By convention, skos:notation is used with a typed literal in the object position of the triple.