As I sometimes need these, I have compiled a list of the valid headers of the web.xml and web-fragment.xml file for servlet version 2.3 until 3.0.
Maybe you find them as handy as I do.
web.xml v2.3
web.xml v2.4
web.xml v2.5
web.xml v3.0
web-fragment.xml:
http://dominikdorn.com/2010/03/web-xml-web-fragment-xml-2-3-2-4-2-5-3-0/
http://stackoverflow.com/questions/17563756/element-listener-class-not-allowed-in-my-web-xml