A more thorough explanation:

Definition: Nomen transcripticium is a Latin term used in Roman law to refer to a creditor's entry of a money debt into a new account after closing another account. This creates a literal contract from an existing obligation, which may or may not have been enforceable. Plural form is nomina transcripticia.

Example: A has had dealings with B in the past, and there is an account in his codex showing a balance against B for 500 aurei. A, with B's permission, closes this account by stating on the opposite page that B has paid the aurei and opens a new account with the statement that he has advanced B the sum of 500 aurei. This represents a nomen transcripticium, where a debt has been transferred from one account to another.

Explanation: Nomen transcripticium is a way to simplify accounts and save disputes about previous transactions. In the example, A and B had multiple contracts in the past, but with nomen transcripticium, they can be novated or extinguished, and one single obligation can be substituted in their place. This offers advantages to both parties and creates a new enforceable contract.