developer notes - How to improve your application compatibility
enable StrictServletCompliance
http://www.tomcatexpert.com/blog/2011/08/03/4-mistakes-avoid-apache-tomcat#comment-4064
Developing and Deploying on Multiple Servlet Containers[]
While it would be ideal to standardize your entire web application stack on one servlet container, the reality is that many organizations use a variety of application servers. In the case where developers are writing the applications on Tomcat, and they may not be deployed on Tomcat, they can avoid future cross-compatibility issues by setting the system property for StrictServletCompliance. This property changes a series of system defaults to follow the servlet specification very strictly to ensure portability. For more information on configuring StrictServletCompliance see the official documentation.
4 mistakes to avoid on tomcat;
http://www.tomcatexpert.com/blog/2011/08/03/4-mistakes-avoid-apache-tomcat#comment-4064