Guys if I am reading this post correctly, we should no longer promote a site on which we have adsense. I would take that to mean sig links are included.

Agree or dis-agree?

The post is only specific to referral units, which are the AdSense version of affiliate links. You're fine linking to a site that has regular AdSense ads though the usual rules of AdSense would still apply like not specifically asking someone to click on an ad, etc.

vangogh is right

only specific to referral units, which are the AdSense version of affiliate links.

To clarify, referral units are when you offer a link for another webmaster to sign up???

If you look in AdSense and click the Setup tab you'll a see a link to Referrals. It's mostly a bunch of different products/services you can promote. Basically it's an affiliate program through AdSense. You link to a product, someone clicks and buys, you get a cut.

I think getting others to sign up for AdSense is considered something different.

if 9 could not have sites with Adsense in sig link, that would mean, that my signature would be totally empty

I use Adsense on the most of my sites, not because I want to profit from it, but cause Adsense is just "must have" for my sites - something like footer, header, blogroll for others...