Operation Oaktree

Operation Oaktree is a project to develop and distribute special little biological modules called Assisted Combination Of Rapid Nitrogen or ACORNs. These are scattered within a forested area and lead to arboriation.

clever chap

Or perhaps a military operation? FBI codename?

Where did you see the term used?

No, serioisly. Operation Oaktree was a an escape line set up for downed British flyers in September 1942 by MI9 and Russian ex-pat Val Williams...a fascinating story.

http://www.conscript-heroes.com/MI9-03.html

There have been quite a few different "Operation Oaktrees", and I see the questioner asks "What is Operation Oaktree?"

Quite true my dear Doctor Watson, however it is merely child's play to deduce from Brian M's various threads that he is deep in a WWII paper and therefore the proper Operation Oaktree is the vaunted operation set up by the brave lads in MI9 in 1942