If you read the forums rules, it basically states no comercial links. But some users are doing it in their signature tags. Those users probably have some type of agreement with www.mnflyfishing.com and are allowed to do it.
The forums rules were changed so that any registered user of www.mnflyfishing.com is allowed to add commercial links to other sites, whether its to promote a product or a business, links are allowed in your posts as well.
Registered users are also allowed to add links to their signature tags as well. We encourage businesses to add their business name and/or website to their signature tags. Businesses should take advantage of this to promote themselves and their business.