The official form of notification prepared at the conclusion of an inspection (without review by FDA management) listing observations of perceived violations of Good Manufacturing Practices that may constitute violations of law in the opinion of an inspector. Originally intended to inform companies of possible product adulteration, they must be replied to satisfactorily and/or corrective action taken in order to alleviate any offensive notification and avoid action from the FDA. Form 483s can lead to withholding of product approvals and plant shut-downs, may come into play in due diligence phases of acquisitions and mergers, and can potentially cost companies money.