August 2010: An Antipattern is a characterization of a common software flaw. As you construct models, you should be alert for antipatterns and correct them. When you find an antipattern, substitute the correction. Universal antipatterns are antipatterns that you should avoid for all applications. This chapter is from the new book Patterns of Data Modeling by Michael Blaha, CRC Press, 2010. All rights reserved. This chapter is posted on odbms.org with the permission of the author and publisher. This is the second of three chapters that will be posted over the upcoming months.