English to German Law/Patents Law: Contract(s)

Kontext:
The Subscriber is not an organization (i) the income of which is exempt from taxation under Section 401 or 501 of the Code or (ii) that generally is taxed on its income under the Code only to the extent that it is engaged in an **“unrelated trade or business” *** within the meaning of Section 513(a) of the Code.

Wer kann mir hier weiterhelfen und mir sagen, wie ich diesen Begriff am besten übersetze? Danke für Eure Hilfe!