OGC Definitions Service (Beta)

http://www.opengis.net/def/vertical-datum-type/ogc/1.0/

http://www.opengis.net/def/vertical-datum-type/ogc/1.0/

label http://www.opengis.net/def/vertical-datum-type/ogc/1.0/ more like this
type
Collection
is primary topic of 1.0
same as
OGC Vertical Datum Types 1.0
same as 1.0