xmlns:atom="http://www.w3.org/2005/Atom"
20. For the purposes of paragraph 64(2) of the Act (defence by the Commissioners that repayment by them of an amount claimed would unjustly enrich the claimant) reimbursement arrangements made by a claimant shall be disregarded except where they—
(a)include the provisions described in regulation 21, and
(b)are supported by the undertakings described in regulation 25.