Codenamed Operational Areas in WW2

Hello Forum,

Doing some research on an Airframe that in late 1941 was sent to carry out an operation in “Area Knapsack” according to the ORB.

Has anybody come across this term before? It’s strange to me as all other targets of further operations have the targets in France, Germany and Holland listed by destination.

Am wondering if this was possibly a training area within the U.K.?

FB