Wiley Blount Rutledge, Claridge Apartments Company v. Commissioner of Internal Revenue…
“ So far as respects the Government's concern over the possible discriminations which will be created between taxpayers by acceptance of petitioner's view, it is perhaps enough to say that some such discrimination is inevitable with whatever solution may be accepted; and we think what follows from applying Sections 268 and 270 only to 'pending proceedings' not only is preferable to any other but is most consistent with the normal course of legislation. Retroactivity, even where permissible, is not favored, except upon the clearest mandate. ”
