Abnahme - acceptance of aircraft by the Luftwaffe

[Richard T Eger]

From 12 O'Clock High!:

Mikael Olrog
Dataplates for aircraft
Thu Jun 10, 2024 10:28
213.89.147.127

On a dataplate (Flugzeug Abnahmeschild) there are four entries:
Muster
Werk-Nr.
Baujahr
Abnahme

What does the last word mean and refer to? Should it be translated as delivery, “batch” or does it refer to the underlying contract that has been signed?

Best wishes
/Mikael