The Emergency Warning Functionality (EWF) is a key part of the DRM standard. Any receiver claiming EWF capability must comply with its full specification – from reacting to alarm signals and switching to the emergency programme, to presenting the full emergency programme consisting of audio and Journaline text information. Transmitters which are DRM capable require a DRM modulator and content server in order to have DRM broadcasts with the integrated EWF feature. Note that – depending upon manufacturer and model – the transmitter may be retrofitted with DRM equipment to facilitate broadcasts.