Except for the U.S., transfer pricing law frequently includes a provision that references the O.E.C.D. T.P. Guidelines as the guidance that must be used to interpret other provisions of relevant law. Nonetheless, national tax administrations publish their own interpretive guides to the O.E.C.D. T.P. Guidelines, thereby adding to a body of administrative guidance that can vary from country to country. The European Commission has recently proposed a Council Directive on transfer pricing released as part of the Business in Europe: Framework for Income Taxation (“B.E.F.I.T.”). The Directive proposes to codify the arm’s length principle and elements of its interpretation from the O.E.C.D. T.P. Guidelines. This elevates the O.E.C.D. T.P. Guidelines into E.U. law, thereby making them more than an arm’s length principle interpretive standard. It does so with several subtle and not-so-subtle variations. Michael Peggs and Michael Bennett caution that making soft law into hard law impairs the ability of tax administrations to compromise on points of controversy.