Combat service support
The term combat service support (or CSS) is utilized by numerous military organizations throughout the world to describe entities that provide direct and indirect sustainment services to the groups that engage (or are potentially to be engaged) in combat. United Kingdom. Defense Secretary Philip Hammond has described the United Kingdom's armed forces as having "teeth", units that are trained and equipped for actual fighting, that cannot function without an able, innovative "tail", units providing assistance such as logistical and transport capabilities. Specific groups involved in the U.K. armed forces include the Royal Army Medical Corps  and Royal Logistic Corps. United States. Also known as (CSS) falls under the umbrella of the United States Department of Defense providing the following support activities to a military division, brigade, battalion and other formations. In the United States, the term combat service support has been phased-out in favor of the term "sustainment." Australia. Within the Australian Army, combat service support is provided to combat elements at various levels: first line (organic to battalion or regimental level), second line (at brigade level), and third line (at formation or higher). Thus, for example an infantry unit such as the 5th  Battalion, Royal Australian Regiment will include a logistics company which fills supply, transportation and maintenance functions, while a combat brigade, such as the 7th Brigade, will be supported by a combat service support battalion such as the 7th Combat Service Support Battalion. At formation level, a CSS brigade – the 17th Sustainment Brigade – will provide health, signals, catering, transport, and other service support requirements.