A.R.S. § 33-815

Every trust deed, substitution of trustee, notice of resignation of trustee, request for notice, assignment of beneficial interest under a trust deed, notice of sale, cancellation of notice of sale or deed of release entitled to recordation under the provisions of this chapter shall be indexed in the same manner as mortgages, with the trustor indexed as mortgagor, and if the name of the beneficiary appears on the instrument being recorded, his name or that of his successor shall be indexed as mortgagee. If the name of the beneficiary does not appear on the instrument being recorded the name of the trustee, or his successor, shall be indexed as mortgagee.