Forums & message boards
An internet forum, or message board, is a discussion website which allows users to hold conversations in the form of posted messages.
Most forums required users to register with the site before posting messages, though some do not.
There is a large plefora of forum software available which once installed onto a webserver allow a website to offer forum functionality.
Popular forum software includes phpBB and vBulletin. These forum software’s usually leave a very clear footprint, and often suffer from poor spam filters (such as captcha). This means forums are often targeted by black hat SEO tools in generating spam links on mass.
Many forums allow users to add a signature to their account which appears under each and every post they make to the forum.
When used naturally these signatures would contain ‘witty’ phrases or links to the user’s personal or hobby website.
Forum signatures though have been abused to place manipulative links. These manipulative links utilise commercial anchor text and often link straight through to commercial landing pages.
Depending on the forum software used, these links sometimes automatically adopt rel=”nofollow”, though many do not.
At one point, it was possible to purchase forum signature links as a package, with your paid for links appearing across many different forum users posts.
If you still have control over the account which has placed these manipulative links they should be removed. Alternatively, contact the forum admin to ask for the links to be removed from the users profile. This though is unlikely to happen.
If the link cannot be removed then, if possible, rel=”nofollow” should be added to these links. Again, this is unlikely to be undertaken by the forum admin for you, so these links need to be disavowed.
Many forums allow users to post links straight into their forum posts, though some will insist on a minimum post count before any link can be added.
Many forums will attempt to obfuscate user links by automatically reforming the link into a link that points to an internal URL, but 301 redirects to the intended destination. For example: http://www.forumdomain.com/link?=http://www.useraddedlink.com. These links should be treated the same as standard links.
Some forums also automatically add rel=”nofollow” to any links added to forum posts.
When placed naturally, the majority of forum post links are just simply URLs. Forum users need to post specific code into their forum postings to get the links to feature anchor text. As such, broadly speaking, most real users do not bother adding the anchor text.
Often, forums posts can be a great source of natural links. The links are naturally earned recommendations from a real human being. If the website itself though is a reputable one, and the forum thread itself is in some way related to the linked to page, then these links can remain.
Generally speaking most forum link, even those achieved naturally, do not pass much link authority to the linked to page. Unfortunately, natural forum post links can often be found surrounded by manipulative links, or hosted on a website that is of low quality.
With these two facts in mind, if you have any concerns in regards to forum post links simply disavow them.
Within forums it is normal to find a page(s) which lists all of the users registered on the forum in a large table, along with additional information about each user, such as their location and, importantly, their personal website URL.
These links are often have rel=”nofollow” automatically attached to them, but in many instances older installs of forums do not.
These forum profile links are often exploited by black hat SEO link generating software. In most cases these links will not be offering any value in terms of link authority, and could likely be viewed as manipulative, and as such should be removed and disavowed.
Disavowing on URL or domain level
The problem with disavowing forum links on a URL level is the amount of pages that the link can be found on. Given the complex structure of much forum software, the URLs on which the links reside may also quickly change (see pagination and mobile sites).
Disavowing these links on a domain level is the obvious solution to this. Bare in mind though the ‘opportunity cost’ of disavowing an entire domain. Any link to your site elsewhere on the domain beyond the forum will also lose its value. The potential value of any link like this needs to be weighed up against the time it will take you to identify all of the forum URLs that need to be individually disavowed.