Treatment of connected persons may be consolidated to determine tax benefit, allowing look-through of arrangements and disregarding accommodating parties. Section 99 directs that, for determining whether a tax benefit exists, connected persons may be treated as one person; an accommodating party may be disregarded; an accommodating party and any other party may be treated as one and the same person; and the arrangement may be looked through by disregarding any corporate structure to ascertain the substance of transactions.