Despite the fact that all external links are nofollow, some still post links for the wrong motives.
True, the FAQ/Rules don't have a specific "link policy", rather, much is left to the judgement of Moderators.
Zero Tolerance for Spam
SitePoint Forums have zero tolerance towards spam. Spammers are not welcome.
SitePoint Forums were created with the purpose of helping others, discussing web design and development and providing a nurturing environment for improving our skills. The forum should not be used as a promotion tool.
This forum includes a number of features to discourage spammers.
Spammers may be warned, infracted or banned at our discretion.
read - if you link drop for the wrong reason, it's SPAM
Asking for critiques
To post a request for a critique, you should first have critiqued others' work. You can read more about the requirements here: here.
read - as long as you meet the criteria, a link is needed to allow for Review.
When you post, don’t promote a site or a product and don’t link to your site unless the resource genuinely adds value to the discussion. If a moderator thinks that your link does not add value, it will be treated as self-promotion and deleted. Self promotion may earn you a warning or infraction.
Link to an article that you may have published on your own site and that answers a question posted in a thread
Link to an under development site for which you are requesting input ([reviews and critiques forum](http://www.sitepoint.com/forums/forumdisplay.php?f=90))
Announce an industry event - provided you keep it factual and not overly spammy
You may not:
Promote your services through a descriptive dialog
Point members to a site linked through your signature
Invite members to PM you for a service
Post a question for the express purpose of concocting a scenario that invites yourself (or a friend or colleague) to post a link to your own site
Suggest your product as an answer to a request or search for all the threads that deal with your line of business (old and new) to expose your signature.
Affiliate links, coupons, and offers
Affiliate links, coupons, offers are not welcome. DO NOT:
Post coupon codes, discounts, offers
Ask for coupons, codes, discounts, invitations to services, etc.
Post affiliate links. Links to Outwar and similar types of schemes are acceptable, as these are links to games. However, it should be obvious from the outset where the links lead to.
This is a serious offence that will often earn you an infraction or banning.
Piracy, warez, adult sites, and illegal content
No sharing of warez or pirated material, please. It is not cool. Likewise, don’t post any work (even a small piece of it) unless you have express permission from the owner or creator of the piece or work. You’ll be responsible for copyright infringement -- not us. It is better if you link to it. It will save you some lawyers’ fees!
Additionally, links to adult sites are not allowed.
SitePoint may also remove discussions that are thought to violate applicable law or that may be harmful to other members, the sites that comprise SitePoint, or the rights of SitePoint Pty. Ltd. or others.
read - if a Moderator(s) believe a post was made re the "you may", no problem. if believed made re the "may not" the post may result in a Warning, Infraction, or Ban
Rule of thumb, if in doubt PM a Moderator and ask before making the post.