http://finregont.com/fro/xbrl/XLink.ttl#UseEnum
Class 'xlink:Use enum'

http://www.xbrl.org/2003/XLink#useEnum

owl:Class

Enumerated values for the use attribute on extended link arcs.

Use enum

dtype:value max 1

dtype:value only xsd:NMTOKEN

dtype:Enumerated value

{xlink:optional , xlink:prohibited}

References
as rdfs:subClassOf (xlink:Arc type)