A court of equity looks to the substance of a transaction and not to its outward form. It treats as done what the parties meant to do.
A borrower hands over the title deeds of his house to a lender as security for a loan, without a registered mortgage. Equity treats it as a mortgage.
Section 58(f) of the Transfer of Property Act, 1882: a mortgage by deposit of title deeds.
Asked with the mortgage by deposit of title deeds.
Substance over form.
Equity gives effect to the real intention of the parties.