A defter was a type of tax register and land cadastre in the Ottoman Empire.
[1] The term is derived from Greek diphthera διφθέρα, literally 'processed animal skin, leather, fur', meaning a book, having pages of goat parchment[2] used along with papyrus as paper in Ancient Greece, borrowed into Arabic as دفتر: daftar, meaning a register or a notebook.
The information collected could vary, but tahrir defterleri typically included details of villages, dwellings, household heads (adult males and widows), ethnicity/religion (because these could affect tax liabilities/exemptions), and land use.
[4] Each town had a defter and typically an officiator or someone in an administrative role to determine whether the information should be recorded.
[5] These records are useful for historians because such information allows for a more in-depth understanding of land ownership among Ottomans.