1. The Classification (FOUO): The marking "FOUO" (For Official Use Only) indicated that the document contained information that was not classified for national security reasons (like Top Secret) but was not intended for public distribution. This usually covered sensitive operational tactics, specific equipment capabilities, or details that could be detrimental to operations if widely disseminated. Today, while many FOUO documents are technically restricted, digital copies of this specific manual have circulated widely among military historians and enthusiasts.

2. Doctrine Shift: In 1999, the Army was transitioning from the open-field battles of the Cold War era to the "Three Block War" concept—where soldiers might be conducting humanitarian aid, peacekeeping, and lethal combat simultaneously within the span of three city blocks. This manual bridged the gap between traditional Special Forces doctrine and the reality of modern, non-linear urban battlefields.

By late 1999, three factors converged:

Thus, FM 31-28 was drafted as an advanced manual—assuming mastery of basic urban combat—and restricted to FOUO to protect tactical techniques, such as specific breaching methods, rooftop interdiction, and subterranean warfare.

The manual is structured to provide a "graduate-level" education in urban warfare, moving beyond basic rifle marksmanship into complex operational planning.

1. Specialized Equipment and Weapons: A significant portion of the manual details equipment specific to Special Forces operations. This includes:

2. Tactical Movement: The manual breaks down movement at the individual, team, and unit levels. It emphasizes:

3. Combat in Built-Up Areas: The text covers the nuances of fighting inside structures, including:

4. Integration of Indigenous Forces: As a Special Forces manual, there is an underlying theme of working with partner forces. It touches on how to train and lead indigenous troops in urban combat, a core tenet of the Green Berets' Unconventional Warfare mission.