49 CFR §33.62

1. (a)A Directive is an official action that requires a person to take or refrain from taking certain actions in accordance with its provisions.
2. (b)A person must comply with each Directive issued. However, a person may not use or extend a Directive to obtain any items from a supplier, unless expressly authorized to do so in the Directive.
3. (c)A Priorities Directive takes precedence over all DX-rated orders, DO-rated orders, and unrated orders previously or subsequently received, unless a contrary instruction appears in the Directive.
4. (d)An Allocations Directive takes precedence over all Priorities Directives, DX-rated orders, DO-rated orders, and unrated orders previously or subsequently received, unless a contrary instruction appears in the Directive.