I traded link with one high PR site. When i use my software to check my link it appeared "rel='nofollow' detected on page".. what is that mean?
It means you have a link for traffic, rather then PR assistance. It's also something that google is wanting done one "paid" links, which they seem to be clumping in link trades with paid now. Minstrel explains it pretty good here: Google ups the ante... again... As for the meaning of nofollow check out these threads: META NOFOLLOW - Help me understand What's the meaning of "external nofollow" Are NoFollow links counted as backlinks? rel=nofollow There are many others...