Which of the following is NOT a remark but a restriction in the CAS brief?

In the context of a Close Air Support (CAS) brief, a restriction refers to specific limitations that are imposed on air operations for safety or operational effectiveness, while remarks generally provide additional information that can guide the operation but do not impose any restrictions. The correct choice indicates that Controlled Access Areas (ACAs) are indeed remarks rather than restrictions.

LTL (Lowest Tactical Level) and PTL (Primary Tactical Level) are considered restrictions because they denote operational boundaries or parameters that air support personnel must adhere to when planning and executing missions. Additionally, a Surface-to-Air Threat is also classified as a restriction since it outlines potential threats that could limit operations.

In contrast, ACAs serve as informative cues, highlighting areas that require special considerations but do not impose direct limitations. They are meant to assist commanders by drawing attention to significant factors without restricting the air support operation directly, which is why ACAs stand apart as remarks rather than restrictions within the CAS brief.