Trading Forum - The Basic Rules
Since so many are unfamiliar with the agreements they agreed to and neglect reading the Rules and Guidelines just under the discussions. I'm pinning this very simple and easy to follow list of rules to help prevent scams, breaking the agreements you agreed to when setting up Steam, or our own Steam Group Rules & Chat Room Rules.

Also for those of you who are trading/offering/selling Game-keys it is not only up to the Steam Trading Card Group what is/isn't acceptable but it helps to read your Steam Subscriber Agreement specifically Article 10. I also recommend reading the software's EULA and 3rd party sites Rules & Regulations/F.A.Q./ToS/etc like HumbleBundle which clearly states that unless you mark your purchase as a gift you are unable to give away excess keys whether they be Steam or Origin.