AviationTire Air Law And Atc Procedures Rules Of The Air (Based On Annex 2) Signals Q 2 / 5

The white dumb-bell with black perpendicular bar indicates that:

landing, take-off and taxiing is allowed on runway and/or taxiway only
taxiing need not be confined to the taxiways
glider flying is performed outside the landing area
this aerodrome is using parallel runways