Wow - glad that helped. So - the different types of compatibility have to do with 1) whether the form will be used in the browser or in the InfoPath application and 2) what version of SharePoint / InfoPath you are targeting. So - if you have a SharePoint 2010 site and you are publishing the form for use in the browser, you'd select Web Browser (2010) [that may not be the exact wording, but you get the idea]. The versions without a year in them are whatever the latest version is for your installation of InfoPath. If you are using InfoPath 2010 designer, for example, you'd only see 2003 / 2007 and versions without a year listed. In InfoPath 2013, you see 2003 / 2007 / 2010 and options without a year, which would be 2013. Does that make sense? It is sort of confounding, I know....
Hilary Stoupa
