1. Institutions shall use the SEC-IRBA to calculate risk-weighted exposure amounts in relation to a securitisation position where the following conditions are met:
(a) the position is backed by an IRB pool or a mixed pool, provided that, in the latter case, the institution is able to calculate KIRB in accordance with Section 3 on a minimum of 95 % of the underlying exposure amount;
(b) there is sufficient information available in relation to the underlying exposures of the securitisation for the institution to be able to calculate KIRB; and
(c) the institution has not been precluded from using the SEC-IRBA in relation to a specified securitisation position in accordance with paragraph 2.
2. Competent authorities may on a case-by-case basis preclude the use of the SEC-IRBA where securitisations have highly complex or risky features. For these purposes, the following may be regarded as highly complex or risky features:
(a) credit enhancement that can be eroded for reasons other than portfolio losses;
(b) pools of underlying exposures with a high degree of internal correlation as a result of concentrated exposures to single sectors or geographical areas;
(c) transactions where the repayment of the securitisation positions is highly dependent on risk drivers not reflected in KIRB; or
(d) highly complex loss allocations between tranches.