These graphics could work similarly to w3 html / CSS validation, clicking on them would take you to a php page that displayed the database entry on postnuke.com showing the module in question was postnuke validated.
This would enable the team to promote a voluntary standard for postnuke modules, and also "move the goalposts" if necessary by publishing new standards to correspond to necessary changes in the PostNuke infrastructure (as w3 also do with HTML and CSS versions).
So "PostNuke 7.1 Valid" images with links to postnuke.com to back it up !! Any takers ?