Can British units trace general supply from the Belgian factory at Antwerpen?
Rule 11E states that a unit may only trace a supply line to a factory or HQ of the same nationality unless it is a minor power tracing to a cooperating major power. The factory is a friendly-owned factory and up to 14 REs of units from each major power is able to cooperate with each other major power on its side (Rule 37E2). However, Belgium is a minor power, so 37E2 doesn’t apply. So the factory would not be a general supply source for the British.