This is a guide for writing software requirements specifications. It describer; the necessary content and qualities of a good Software Requirements Specification (SRS) and presents a prototype SRS outline. This guide does not specify industry-wide SRS standards nor state mandatory SRS requirements. This guide is written under the premise that the current state of the art does not warrant or support such a formal standards document. This guide is applicable to in-house and commercial software products. Special care, however, should be used in its application because: (1) This guide is aimed at specifying requirements of software to be developed. Application of this material to already developed software is counter-productive. (2) This guide does not cover the specification of requirements for software being developed using the techniques of rapid prototyping.