  Reconfigurable Intelligent Surfaces (RISs) are a novel form of ultra-low
power devices that are capable to increase the communication data rates as well
as the cell coverage in a cost- and energy-efficient way. This is attributed to
their programmable operation that enables them to dynamically manipulate the
wireless propagation environment, a feature that has lately inspired numerous
research investigations and applications. To pave the way to the formal
standardization of RISs, the European Telecommunications Standards Institute
(ETSI) launched the Industry Specification Group (ISG) on the RIS technology in
September 2021. This article provides a comprehensive overview of the status of
the work conducted by the ETSI ISG RIS, covering typical deployment scenarios
of reconfigurable metasurfaces, use cases and operating applications,
requirements, emerging hardware architectures and operating modes, as well as
the latest insights regarding future directions of RISs and the resulting smart
wireless environments.
