IEC 62988:2018 establishes requirements relevant to the selection and use of wireless devices in instrumentation and control (I&C) systems important to safety used in nuclear power plants (NPPs). Those I&C systems may fully consist of wireless devices. This document applies to the I&C of new NPPs and to backfit of I&C in existing NPPs. Every wireless device or wireless system that is important to safety is in the scope of this document. Both fixed and mobile devices and all data types (voice, process data, etc.) are included within the scope if they provide a safety classified function. This document restricts the use of wireless devices to systems supporting category C functions according to IEC 61226, excluding explicitly their use for categories A and B. Non-safety devices and systems may use this document as guidelines, for example to ensure that important to safety devices are not disturbed.