For those who have a blog, comment spam has been the bane of online existence. I actually turned comments off on my blog following a rash of porn-related comment spam that had my parents asking questions.

If you are reading this and are not sure what comment spam is, think of adds for “enlargement” pills in the comment section of a blog, complete with explicit description of the product’s effectiveness and a link to the site where you can buy.

I enabled comments after Six Apart released TypeKey, a service that requires registration before posting comments to a blog, but that only partly solved the problem. Spammers soon found a way to lessen the impact of TypeKey’s registration service, and comment spam continued (and got worse for those not using a system like TypeKey).

Last week, in answer to many blogger’s prayers, Google released a new standard for limiting the effectiveness of comment spam. By inserting the words rel=”nofollow” into a hyperlink, one could effectively tell the Google search spider not to index the link. Because Google ranks web pages based on the number of links to it (among other metrics), the “nofollow” attribute effectively eliminates the reason for leaving comment spam.

The response was immediate. Many blog-related software companies pledged their support, and the other big search engines agreed to follow suit. You can read about the companies that added support for the new standard in Google’s announcement.