Generally Accepted Accounting Principles. The accounting standards and best practice in a jurisdiction. For example, in the UK, UK GAAP is understood to mean compliance with UK company laws, accounting standards and best practice.
Acting honestly and fairly towards another party. A civil law concept that is similar to acting reasonably in common law.
The law that regulates an agreement and any disputes that may arise out of it. The Governing Law provision is normally found in the general or miscellaneous section towards the end of an agreement.