@Charles *********
some rumor come that for the soft thai power, you may need to provide appointment or lesson booking. ( they will probably do later some more checking, probably more for the soft thai power dtv .. ), for now they will probably ask you nothing ( as the dtv was delivered for something already checked recently .. ).
Globaly i think you always ( for the 5 years ) be able to prove that the dtv is still used in the purpose of the delivered dtv ....