A more thorough explanation:

Definition: Nomina debitorum is a Latin term that means "entries (in a ledger) of names of debtors." It refers to records of debt in Roman law. See also nomen transcripticium.

Definition: Nomen transcripticium is a Latin term that means "entry (in an account) transferred." It refers to a creditor's entry of a money debt into a new account (expensilatio) after closing another account, thereby creating, with the debtor's permission, a literal contract from an existing obligation, which may or may not have been enforceable. Pl. nomina transcripticia.

For example, let's say A has had dealings with B in the past, and there is an account in A's ledger showing a balance against B for 500 aurei. A, with B's consent, closes this account by stating on the opposite page (contrary to fact) that B has paid the aurei and opens a new account with the statement (contrary to strict fact) that he has advanced to B the sum of 500 aurei. This process represents a nomen transcripticium, where a debt has been transferred from one account to another. In effect, the old contracts between A and B have been novated, i.e. extinguished, and one single obligation has been substituted in their place. This course offers many advantages to both parties, as it simplifies the accounts and saves disputes about the previous transactions.

In summary, nomina debitorum and nomen transcripticium are terms used in Roman law to refer to records of debt and a creditor's entry of a money debt into a new account, respectively.