Prior to the installation and operation of an antenna construction a licence or notification is required, as well as a building construction permit. The obligation of licensing is largely determined by the characteristics of the antenna construction irrespective of its intended use, commercial or otherwise. In addition to antenna constructions, any masts and antenna accessories (supporting structures, struts, etc.) are included in the definition of antenna constructions. Certain types of antenna constructions are allowed to be installed and operate without a licence from EETT. These are, for example, antenna constructions for television signal reception and antenna constructions of the Hellenic Civil Aviation Authority (CAA), security forces and ministries.