D. Representations and Warranties

You represent and warrant to us that you have sufficient rights in all User Generated Content to grant Valve and other affected parties the licenses described under A. and B. above or in any license terms specific to the applicable Workshop-Enabled App or Workshop page. This includes, without limitation, any kind of intellectual property rights or other proprietary or personal rights affected by or included in the User Generated Content. In particular, with respect to Workshop Contributions, you represent and warrant that the Workshop Contribution was originally created by you (or, with respect to a Workshop Contribution to which others contributed besides you, by you and the other contributors, and in such case that you have the right to submit such Workshop Contribution on behalf of those other contributors).

I just taught someone how to do this properly, I never considered the issue of credit. Good thing I never did any myself ;d