You're picking nits here. As far as RadioReference (and the law) is concerned, if the purpose is to hide the content of a transmission from unauthorized listeners, it's encryption. And as I noted earlier, we do not track encryption type, only the fact that it is there.I think a lot of people missed a BIG fact here. The OP said that he was talking about rolled speech inversion. This in not encryption and can be unscrambled very easy. See this WIKI . -Edit For anyone who is wondering "scrambling" is different from Encryption in two major ways. The first is that it is not legal for anyone to Decrypt a signal for which they are not the intended recipient. This does not apply to a scrambled signal. The second is the way that the two systems work. A scrambled system/channel simply applies filters to the audio to make it hard to understand and in most cases it can be un done with a small effort. Encryption uses a crypto to encode digital audio data. A private key is stored in the transmitter and in the receiver that allows for the process to take place.