[class101]

What does vbseo do in general ? or about the <!-- google_ad_section_start --> you mean ?
That's not the main feature of vbseo, just one of the large options available in the vbseo product but about this adsense code, vbseo automatically enclose

<!-- google_ad_section_start --><!-- google_ad_section_end -->

in front of relevant text of the forum and threads, for example, titles, message body, Relevant Replacements (vbseo feature to add relevant text to each thread/forums), all what is relevant to the page to have different ads matching the thread and forum subjects. The cool features is it adds also

<!-- google_ad_section_start(weight=ignore) --><!-- google_ad_section_end -->

wich is the code used by adsense to ignore part of the page, I see on the source it adds this on the member's username & signatures, to not have the members title and signatures altering the ads content, very excellent feature you could add yeah , could feat very well with vb ads heheh and no copyrights on this heheh

Let me know if you wanna much informations, I can work to see where it adds exactly theses codes and you could reproduce the same. Or if you wanna work on yours own RedTyger that's not so hard you can see the instruction directly from Google here.