This appendix reviews the basic results for many of the distributions which are useful in mobile communications and is associated mainly with Chapter 2. The distributions are motivated by the need for descriptions for the electrical and field signals and the signal coverage and communications outage, etc. Gaussian statistics form the basis of most of the distributions. No physical modelling is included here so that the statistics are confined to envelope and power, and some phase distributions. The distributions of phase derivatives, for example, from physical models, are treated in the text and make use of the results here. The overbar and the angle brackets are used interchangeably with the usual expectation operator for simplicity here. Similarly, whereas in classical statistical notation, upper case letters are normally used for a random variable, this is not adhered to in this text.