A legal instrument which, consistent with 31 U.S.C. 6304, is used to enter into a relationship:

(a) Of which the principal purpose is to transfer a thing of value to the recipient to carry out a public purpose of support or stimulation authorized by a law of the United States, rather than to acquire property or services for the Department of Defense's direct benefit or use.

(b) In which substantial involvement is not expected between the Department of Defense and the recipient when carrying out the activity contemplated by the grant.