All clear is the signal, generally given by a civil defence siren, which indicates that an air raid or other hazard has finished and that it is safe for civilians to leave their shelters; it is commonly used in radios as well.
All clear is the signal, generally given by a civil defence siren, which indicates that an air raid or other hazard has finished and that it is safe for civilians to leave their shelters; it is commonly used in radios as well. (en)
All clear is the signal, generally given by a civil defence siren, which indicates that an air raid or other hazard has finished and that it is safe for civilians to leave their shelters; it is commonly used in radios as well. (en)