Literis obligatio refers to a contract of nomen. Such a contract is constituted by a writing. An example is a creditor who owns a debt due from a person with respect to a sale, letting, or partnership, that enters the debt in his/ her book as a debt. There are two types of literis obligatio. They are a re in personam and a persona in personam. In a re in personam, a transaction is transferred from a day book into a ledger in the form of a debt under the name of purchaser. In a persona in personam, a debt existing in one nomen heading is transferred to another nomen heading.