[openrailwaymap] "Museumsbahn" / Preserved Track

Hi all, which tags are needed to render a railway as a preserved track ( "Museumsbahn") ? Or what is the best way to show a draisine track in OpenRailwayMap? For instance https://www.openstreetmap.org/way/33651730 is not shown in ORM and I wonder why. Best, Eckhard