The post about the release is here and the full guidlines are here.
Basic Trading Guidelines
- Know who you are trading with: Do not trade with random people you meet on servers as this can often lead to trade scams. Clicking on the avatar image of the user you are trading with will take you to their profile. Make sure it isn't someone who change their name and avatar to imitate someone else.
- Always receive something in a trade: Do not perform a trade in which you are only sending items and not receiving any items in return.
- Utilize the trade limit: Do not agree to trade more than 8 items to another user. This avoids any possibility of ever having to send items to a user and not receive anything in return (see #2)
- Keep your trade within Team Fortress 2: Keep your entire trade within a single trade window - Do not agree to trade things that can't be dragged into the trade window. (Example: Do not trade an Unusual Hat for a gift of Left 4 Dead 2)
- Verify the items: Make sure the items are the real thing by placing your mouse over them and read the description. Make sure they're not items designed to look like a more valuable item through the use of Name Tags or Description Tags -- the description will have red warning text in these cases. The trade dialog will warn you whenever the trade has been changed. Re-check the items whenever changes occur.
- Think a trade is unfair? Don't do it!: Trades that you consider to be unfair after agreeing and accepting a trade are valid trades and will not be undone by Steam Support so ensure you are comfortable with the trade before completing it.
There is only one case where we will revert a trade within Team Fortress 2:
Not Receiving Items: If you agree to a trade within Team Fortress 2 and do not receive any Team Fortress 2 items in return we will be able to reverse this trade and restore the items to your account. If you receive the incorrect item because it was switched out we will not reverse these trades as it is your responsibility to check the trade prior to accepting it. This does not include trades where you agreed to receiving money/other products outside of Team Fortress 2. If you did this you will not receive your items either.
Trades agreed upon outside the scope of the Team Fortress 2 trading system will not be considered scams and you will not receive any unfairly traded items back. Trading outside of Team Fortress 2's system is an at-your-own-risk choice. It is highly recommended that you do not do any trades outside of Team Fortress 2 to avoid this from occurring.
As Valve have made it clear they "highly recommend" you don't perform trades outside the TF2 items system/Steam Official trading (I.E for games, money or other 'Real Life' items), we will not permit trading posts in this forum about such trades. The potential for problems or scams with this sort of trade is much higher and as UKCS does not accept any responsibility for trades organised via these forums, we feel is better to set out a straight ban rather than have people getting into lengthy discussions about the merits or reliability of posts.