Fixing Prices or Commissions:
Agents and brokers in any setting, business or social, should take great care to never even discuss commission rates in any context. It's much better to be safe than sorry in this case.
Boycotting a Competitor for Any Reason:
A couple of brokers are having lunch and discuss the new commission discounting company in town. They both agree that it's a bad thing for business and that they're not going to show that broker's discounted listings. They've probably guilty of a per se offense and couldn't even argue otherwise in court.
Boycotting a Supplier or Vendor:
If a group of the local real estate offices grouped together, even very informally, and pulled their advertising in an effort to force a change of policies and/or advertising rates on the newspaper, they would most likely be guilty of a per se offense of the antitrust statutes.
Attempting to Fix or Control the Cooperative Splits in the Market:
Any agreements between companies that would attempt to set or control the amount or percentage of the splits offered in a market would very likely be a per se violation of antitrust statutes.
Setting or Attempting to Control the Length of Listings:
Discussing or Agreeing to Different Treatment of a Competitor as a Group:
In Short - If You Have the Slightest Doubt You Probably Shouldn't Do It:
Remember, it's considered a per se offense when the government has deemed it definite and egregious damage to the free trade of another. A per se violator cannot even present a defense as to whether it was damaging, whether it restrained trade or not. They're only left with whether they committed the offense or not. If they did, in this instance, they're dead.
If you're in a meeting or even a social gathering, and the conversation turns toward any of these topics, you should leave the area immediately. It would probably also be wise to make it known that the possibility of violation is why you're leaving.

