Which type of defect notice represents a formal warning?

A formal warning in the context of defect notices signifies a serious acknowledgement of an issue that necessitates immediate attention or correction. This type of notification typically outlines specific deficiencies or violations that have been identified, emphasizing the requirement for corrective action to be taken.

When we consider a formal warning, it is more than just a notification; it serves as a crucial step in compliance processes, indicating that non-adherence could lead to further consequences. In contrast, other types of defects, whether classified as minor, major, or major grounded, may not carry the same weight of formality or urgency associated with the term "formal warning." These classifications might address the severity or the nature of the issue but do not encapsulate the formal procedural aspect that a formal warning entails. Thus, it is the formal warning that stands out as the correct answer, as it is specifically designed to communicate a significant level of concern and the expectation of a response.