I was checking out one of my company's website's Webmaster Tools to analyze the cause behind some soft 404 errors and discovered that a few of the older errors had affiliate mp referral tags listed as the relative URLs. Since these are older problems and I don't seem too many of them coming up in the last few months I don't think it's still a problem. I'm just curious if it's possible to cause a soft 404 by improperly copying the campaign or referral tag into the URL.