Which statement is true regarding Supplements in relation to the basic publication?

The statement about Supplements must not be less restrictive than the basic publication is accurate because Supplements serve to enhance or add to the information presented in the basic publication. This ensures that the supplemental information maintains or increases safety and operational standards, rather than lowering them. By requiring that Supplements adhere to or exceed the restrictions and guidelines set forth in the basic publication, it guarantees that any additional processes, procedures, or modifications will uphold the same level of safety and regulatory compliance.

The other choices misrepresent the relationship between Supplements and the basic publication. For example, Supplements are not intended to be less restrictive, as this could compromise safety. They are also comprehensive in scope, not limited to just air traffic control. Furthermore, while Supplements are important references, they are not integrated into the Body Page of the basic publication but rather presented as additional documents.