(g) Unusual circumstances. The regulations in subchapter U of this chapter specify certain allowances that apply in unusual circumstances. While it is difficult to precisely define what unusual circumstances means, this generally refers to specific circumstances that are both rare and unforeseeable. For example, a severe hurricane in the northeastern United States may be considered to be an unusual circumstance, while a less severe hurricane in the southeastern United States may not be. Where the regulations limit an allowance to unusual circumstances, manufacturers and others should not presume that such an allowance will be available to them. Provisions related to unusual circumstances may be described using the phrase normal circumstances, which are those circumstances that are not unusual circumstances.