Multi-employer withdrawal arrangements: guidance from the Pensions Regulator. This version was published in November 2005 and the guidance has since been updated.
This document applies to debts arising as a result of employment-cessation events which are subject to the Occupational Pension Schemes (Employer Debt) Regulations 2005 (SI 2005/678), as they existed before 6 April 2008.
http://www.thepensionsregulator.gov.uk/docs/multi-employerguidance-Nov05.pdf