Last year the number of patent suits in U.S. courts jumped 23%, to a record 1,447. Many of the suits involved small inventors successfully suing large concerns. With that in mind, inventors, entrepreneurs, managers, and patent lawyers will find a timely resource in How to Write a Patent Application, by Jeffrey G. Sheldon (Practising Law Institute, New York City, 212-765-5700, 1992, $155). It covers basics such as disclosure statements, when to file, and how to write the specifications, as well as gives detailed information on patent types -- design, electrical, software, chemical, and biotech. There is also a chapter devoted to filing for patents in foreign countries. The publisher says demand for the volume has been particularly strong from the Japanese. The 700-page book is bound in a loose-leaf format to accommodate a planned supplement. -- Alessandra Bianchi