I cannot understand this concept, please give me some clarity on this.
If I link to a site, and it links to me, then is it a link scheme ?
I see many seo companies link to their other sites, from their sites, and they rank well.
Is it ok to exchange links between the sites I have built ?
and moreover, is it ok to give a link to my w3c html validation page, since it gives back a 'follow' link to me ? the anchor text is my domain name.