What document should ADOs refer to when marking correspondence for special services?

The appropriate document for ADOs (Activity Duty Officers) to refer to when marking correspondence for special services is the Domestic Mail Manual. This manual provides comprehensive guidelines on how to handle various forms of domestic mail, including procedures for marking and routing correspondence that requires special handling or services. It outlines specific requirements for packaging, labeling, and addressing mail to ensure that it is processed correctly and reaches its intended destination in a timely manner.

The Domestic Mail Manual is essential for ensuring that ADOs understand the nuances of mail classification and the different services available, such as priority and express options. This knowledge is crucial for maintaining compliance with postal regulations and achieving efficient mail operations.

Other documents mentioned, while relevant to postal operations in general, do not specifically address the criteria and methods for marking correspondence for special services in the same way that the Domestic Mail Manual does. The Military Mail Manual is focused on military mailing procedures, the Official Mail Guide pertains to the handling of official government correspondence, and the Postal Service Handbook provides broader postal regulations that may not be specific to domestic mailing services.