MELBOURNE (S&P Global Ratings) June 14, 2017--S&P Global Ratings today assigned its ratings to five of the six classes of prime residential mortgage-backed securities (RMBS) issued by Perpetual Corporate Trust Ltd. as trustee for IDOL 2017-1 Trust (see list). IDOL 2017-1 Trust is a securitization of prime residential mortgages originated by ING Bank (Australia) Ltd. The ratings are based on: Our view of the credit risk of the underlying collateral portfolio, including the fact that this is a closed portfolio, which means no further loans will be assigned to the trust after the closing date. Our view that the credit support is sufficient to withstand the stresses we apply. This credit support comprises note subordination and lenders' mortgage insurance policies.