This Manual is a convenient and useful specification aid for anyone concerned with the design, construction, or inspection of fire resistive and sound control systems. Design information is quickly and easily determined. Comparison of these characteristics allows the user to be more accurate in meeting design and code requirements. The data provided are especially useful to builders, architects, code officials, fire service, and insurance personnel. When differences occur between provisions of this Manual and the appropriate building code or regulation, including provisions of other standards referenced in the code or regulation, the most stringent provision shall apply. The systems in this Manual utilize gypsum products to provide fire resistance to walls, partitions, floorceilings, roof-ceilings, columns, beams, girders, and trusses. Systems are classified according to their typical uses and their fire-resistance ratings. Walls, partitions, and floor-ceiling systems are further classified by Sound Transmission Class (STC) or Field Sound Transmission Class (FSTC). The Impact Insulation Class (IIC) is included for many wood framed floor-ceiling systems.