(a) Applicability of federal law. The disclosure requirements of the Truth in Lending Act, 15 U.S.C. §§1601 - 1667f, and its implementing regulation, Regulation Z, 12 C.F.R. Parts 226 and 1026, and specifically 12 C.F.R. §226.18(f) and §1026.18(f), regarding variable rate disclosures, apply according to their terms to some retail installment transactions subject to this chapter.(b) Inconsistency. In the event of any inconsistency or conflict between the disclosure or notice requirements in these provisions and any current or future federal law, regulation, or interpretation, the requirements of the federal law, regulation, or interpretation will control to the extent of the inconsistency.(c) Amount financed. In the model clauses provided by this subchapter, a licensee may replace the term "principal balance" with "amount financed" whenever the amount financed, computed in accordance with federal Regulation Z, is the same as the principal balance computed in accordance with the Texas Finance Code.(d) Annual percentage rate. In the model clauses provided by this subchapter, a licensee may replace the term "contract rate" with "annual percentage rate" whenever the annual percentage rate, computed in accordance with federal Regulation Z, is the same as the contract rate computed in accordance with the Texas Finance Code.