The support page for CPF on the Comodo site links to PDF documentation for v2.3
(some of the info is outdated and invites confusion)
http://www.personalfirewall.comodo.com/support.html?currency=USD®ion=North%20America&country=US
The same condition (outdated info, inviting confusion) exists within the various “knowledgebase” entries:
http://support.comodo.com/index.php?_m=knowledgebase&_a=view&parentcategoryid=13&pcid=2&nav=0,2