IFR pickup standard phraseology

[kaposznyak]

Hi guys.

My question is Europe-related.

So flying VFR, in uncontrolled airspace (Class F) with a Z-type flight plan (first VFR, later at a given point IFR) what is the standard phraseology for changing to IFR?

"Request IFR pickup?"

And most importantly what would be the answer from the flight information officer? Clearly not a clearence...

Cannot find any official source for this situation. And I am a flight information officer

Thanks in advance!