IEC 62047-5:2011 describes terminology, definition, symbols, test methods that can be used to evaluate and determine the essential ratings and characteristic parameters of RF MEMS switches. The statements made in this standardization are also applicable to RF (Radio Frequency) MEMS (Micro-Electro-Mechanical Systems) switches with various structures, contacts (d.c. contact and capacitive contact), configurations (series and shunt), switching networks (SPST, SPDT, DPDT, etc.), and actuation mechanism such as electrostatic, electro-thermal, electromagnetic, piezoelectric, etc. The RF MEMS switches are promising devices in advanced mobile phones with multi-band/mode operation, smart radar systems, reconfigurable RF devices and systems, SDR (Software Defined Radio) phones, test equipments, tunable devices and systems, satellite, etc. The contents of the corrigendum of March 2012 have been included in this copy.