Much of an application on a Mac is configured by a file called Info.plist. You can find the file when
you right click on an application and choose "Show packet content" and descend down in the Content folder.
Apple has a page about all the key/value pairs at http://developer.apple.com/documentation/MacOSX/Conceptual/BPRuntimeConfig/Articles/PListKeys.html.
I was looking for a way to disable the dock icon and Main menu from a "StatusBarApp" (Apple calls them Agents IIUC). But without knowing the right terminology, this is hard to find :)