Any detail reference info on passShellenvironment variable used in the CGI servlet?

[Dan Kim]

Could someone please point me to some reference information on what exactly the passShellenvironment variable does? I want more detail info on it besides what's available on Tomcat 6 CGI How-To doc.

The reason being is had it not been my lucky guess that this variable was the cause of my problem as per my earlier post here:
http://www.coderanch.com/t/440317/Tomcat/Help-with-setting-up-Tomcat#1958814

After doing some google searches, I found others who experienced similar problem. But the suggestion to set the passShellenvironment to "true" wasn't fully explained or why it was needed.

Thanks,
Daniel