Reg O is short for Regulation O, which is a set of rules and regulations established by the Federal Reserve Board to limit loans and extensions of credit that a bank may make to its executive officers, directors, and principal shareholders. The regulation is intended to curb conflicts of interest between a bank and its insiders, protect the safety and soundness of banks, and promote public confidence in the banking system. The specific provisions of Reg O include: 1. Restrictions on loans to executive officers, directors, and principal shareholders. 2. Maximum loan amounts allowed for executive officers and directors. 3. Requirements for reporting of loan information to the Federal Reserve Board. 4. Restrictions on transactions between the bank and its executive officers, directors, and principal shareholders. 5. Prohibition on loans or guarantees from the bank to any company in which an executive officer or director has a financial interest or participates in its management or control.