Radar Climb

[SU-GCM]

Hello guys

that's my first topic to ask about something on pprune
I am an aviation enthusiast from Egypt and lives around 2NM from RWY 05L at Cairo

I usually listen to Cairo Director frequency 119.050
and hear the controllers tell the pilots xxxx,turn Right heading 120 Climb FL110 Radar Climb

what does the expression (Radar Climb) Means ????

I have tried to search document 4444 ? but found nothing regarding this expression :S

thanks for your help