CLOVER is a timing verification system for digital systems. It was designed to handle medium size asynchronous systems, particularly interface systems, but can be used with synchronous systems as well. A wide range of basic components can be used with CLOVER, including user-defined components. To use CLOVER, the designer provides a description of the design in the hardware description language PDL-e and a description of the timing constraints that the design should satisfy in CLOVER's constraint language ATCSL. CLOVER derives an $event^graph$ for the design using an event-based timing simulator and checks the satisfaction of each constraint within the event graph. In this report we present a detailed description on the use of CLOVER from the user perspective. A detailed documentation of all CLOVER's features is given, accompanied by simple but illustrative examples.