Th standard provides ts and definiti used in the context of electromagnic wave propagation elating to the fields of telecommunications@ sensing@astro nomy@ optical waves@ plasma waves@ the ionosphere@ the magnetosphere@ and magnetohydrodynamic acoustic@ and electrostatic waves. Some obsolete terms and definitions will be removed. The language used for some already existing terms will be refined. The standard will also include some additional terms that are commonly accepted in these fields. Purpose The standard will have no purpose clause