In case of an allies capital being captured: (Correct me if I’m wrong)
Say The Gilbert Isles are in Jap hands, along with India (UK capital). If the US liberates Gilbert, then on the US next turn (If India has not been liberated) the US can place an AB/NB there. Gilbert would (temporarily) belong to the US. If India (UK capital) is liberated, Gilbert and its new base would go back to UK. It would be the same for tt that are eligible for IC’s (say Kwangtung).