The tapu resmi was a feudal land-registration tax in the Ottoman Empire. A tapu was the equivalent of a title deed for farmland, in a feudal system where farmers were proprietors rather than outright owners; this would be recorded in a tapu tahrir, a survey of land ownership and land grants which the Ottoman government used to update land-tax records, and which are now valuable to historians. Not all land was subject to the tapu system; iltizam tax-farming was more commonly applied to non-tapu land. A prominent 16th-century legal theorist argued that tapu resmi was contrary to shari'ah law, and was effectively a bribe; however, tapu resmi continued to be used across the Ottoman Empire.