42.When the following minimum operational requirements are satisfied, an institution shall attribute to an unrated position an inferred credit assessment equivalent to the credit assessment of those rated positions (the ‘reference positions’) which are the most senior positions which are in all respects subordinate to the unrated securitisation position in question:U.K.
(a)
the reference positions must be subordinate in all respects to the unrated securitisationposition;
(b)
the maturity of the reference positions must be equal to or longer than that of the unrated position in question; and
(c)
on an ongoing basis, any inferred rating must be updated to reflect any changes in the credit assessment of the reference positions.