Windchill ESI RPC classes and methods are described in detail in the Windchill Enterprise Systems Integration Open Application Programming Interface Guide. The RPC classes use the globally safe namespace, com.ptc.windchill.esi. Customizers should not modify the RPC classes in this namespace or the methods of those classes. Such modifications are subject to being overlaid by future releases of Windchill ESI Customizers may modify the output of the RPC classes and methods using the procedures defined in the preceding sections of this document.