Many of today who claim to embrace blogs DoFollow system. so we also need to know exactly how to tell if a blog is DoFollow or Nofollow status. Of reference that I know about can be summed up like this:

   1. Contain mean that nofollow links are included when we give comments on a blog. The result of the comments that we wrote it, not getting backlinks from blogs, while we know that the backlink is one important element in increasing page rank.
   2. DoFollow is the opposite of nofollow, so the sign was forbidden and replaced with a welcome revoked.
   3. By default settings for a blog is a nofollow comment, meant to reduce spam. But we can alter become DoFollow.
   4. Benefits blog that that system is for the giver DoFollow comments will get a backlink. This course is an additional point to improve pagerank and profits for the owners of blogs is increasing visitors. While the losses if any incoming or existing links on your blog / web links that are considered legitimate by search engines, could be a blog / website is considered a link farm. So that the Pagerank value of your blog / website will be down.
   5. Thus think about nofollow thoroughly want to stay or to change it to DoFollow .. after knowing the advantages and disadvantages ....

While the mode is DoFollow Blog To know or not is by using Mozilla Firefox. then "right click" on people who make comments and click "properties". then see "Relation", if it's an external means DoFollow, NoFollow if these blogs will also be visible there. Or focus on the writings nofollow (after right click). If there are means nofollow, if no means DoFollow.