Joint Expeditionary Force (Maritime)

The Joint Expeditionary Force (Maritime) (or JEF(M)) (formerly the Response Force Task Group (RFTG), and prior to that the Joint Rapid Reaction Force (JRRF)), is the Royal Navy's contribution to the Joint Expeditionary Force (JEF) maintained at very high-readiness and available at short notice to respond to unexpected global events. In addition to the Royal Navy and the Royal Marines, the JEF(M) also includes elements of the British Army and the Royal Air Force.

Source: Wikipedia — Joint Expeditionary Force (Maritime) (CC BY-SA 4.0)