5. Priority in Fixtures: Residual Rule. Subsection (c) [Maine cite subsection (3)] states the residual priority rule, which applies only if one of the other rules does not: A security interest in fixtures is subordinate to a conflicting interest of an encumbrancer or owner of the related real property other than the debtor.

6. Priority in Fixtures: First to File or Record. Subsection (e)(1) [Maine cite subsection (5), paragraph (a)], which follows former Section 9-313(4)(b), contains the usual priority rule of conveyancing, that is, the first to file or record prevails. In order to achieve priority under this rule, however, the security interest must be perfected by a "fixture filing" (defined in Section 9-102 [Maine cite section 9-1102]), i.e., a filing for record in the real property records and indexed therein, so that it will be found in a real-property search.. The condition in subsection (e)(1)(B) [Maine cite subsection (5), paragraph (1), subparagraph (ii)], that the security interest must have had priority over any conflicting interest of a predecessor in title of the conflicting encumbrancer or owner, appears to limit to the first-in-time principle. However, this apparent limitation is nothing other than an expression of the usual rule that a person must be entitled to transfer what he has. Thus, if the fixture security interest is subordinate to a mortgage, it is subordinate to an interest of an assignee of the mortgage, even though the assignment is a later recorded instrument. Similarly if the fixture security interest is subordinate to the rights of an owner, it is subordinate to a subsequent grantee of the owner and likewise subordinate to a subsequent mortgagee of the owner.

7. Priority in Fixtures: Purchase-Money Security Interests. Subsection (d) [Maine cite subsection (4)], which follows former Section 9-313(4)(a), contains the principal exception to the first-to-file-or-record rule of subsection (e)(1) [Maine cite subsection (5), paragraph (a)]. It affords priority to purchase- money security interests in fixtures as against prior recorded real-property interests, provided that the purchase-money security interest is filed as a fixture filing in the real- property records before the goods become fixtures or within 20 days thereafter. This priority corresponds to the purchase-money priority under Section 9-324(a) [Maine cite