Fuel return pipe on the carb

[Flyingpony]

On my Holden 186 engine, the Rocker carb has got one fuel input from the engines mechanical fuel pump. The other fuel pipe attached to the carb immediately next to the input has been terminated off with a short length of fuel hose and a hose clip / bung approach.

Is it safe to run with this other pipe terminated?
What would be it's purpose?
Is it under constant high pressure from the fuel pump?

If this terminated pipe were to accidentally come off or leak too excessively, petrol will be dumped onto the exhaust.

Thanks.