UML is the international standard notation for object-oriented analysis and design.
It is defined by the Object Management Group (www.omg.org) and is currently at release 1.4 with 2.0 expected next year.
UML provides several notations which are described in detail in Ian Graham's Object-Oriented Methods (Addison-Wesley, 2001);
preview:
http://uml.tutorials.trireme.com/
7/11/2002