From the back of the book:
The Advanced Phoenix Command Supplement expands on the rules provided in the Phoenix Command Combat System, allowing players to handle a wide variety of special situations. Each section is modular, making it easy for players to use the appropriate rules, and to select the exact level of game detail desired. More than 20 different sections are included, among them:
Blunt Trauma: When Body Armor stops a bullet, it only stops the penetration; it does not necessarily stop the severe bruising and possible broken bones which may result from the bullet's impact. The wounds caused by non-penetrating rounds, called Blunt Trauma, are fully discussed.
Smoke: A common factor on many battlefields, Smoke provides vital protection from the enemy during dashes across streets and open areas, towards hostile positions, and during retreats. The full effects of Smoke are explained including the duration of Smoke clouds generated by Smoke Grenades, the effects of wind on the cloud, and the partial visibility possible while the smoke clears.
Blind Fire: The standard response to enemy Smoke screens, Blind Fire (firing without being able to see the target) can also be vital in house-to-house fighting, when pinned by enemy fire, or providing harassing fire against unseen opponents.
Among the other sections included are: Ballistic Accuracy; Weapon Reliability and Weapon Damage; the Three Round Burst; Explosive Ammunition; Permanent Disabling Injuries; Effective Minimum Arc; Optical Scopes; Spotting; Cover Generation; Large Scale Battlefields; Leadership; Ground Burst Explosions; Mines and Traps; Time of Flight; Evasive Action; Recoil Recovery; Off Hand Fire; Free Actions; Skills; Training; and Experience.