Which of the following describes "prescribable items" related to uniforms?

The definition of "prescribable items" in relation to uniforms specifically refers to those items that may be directed or authorized for wear alongside the basic uniform. This means they can include additional components such as ribbons, badges, or other accoutrements that complement the basic standard uniform but are not mandatory for all personnel. These items often enhance the uniform's functional or ceremonial aspects and can vary based on specific unit regulations or mission requirements.

In contrast, the other options do not accurately capture the essence of prescribable items. Items worn only during ceremonies, for example, imply a limited scope that does not align with the broader application of prescribable items. Exclusivity to officers indicates that such items are not meant for all service members, which contradicts the inclusive definition of prescribable items. Lastly, the notion of items that cannot be altered does not pertain to prescriptiveness; items may still be prescribable while permitting specific modifications in certain contexts. Thus, the correct identification of prescribable items as those permitted to be authorized with the uniform encompasses their flexible and inclusive nature.