Can I advertise someone else's listing?
The rule is you must have the seller's permission to advertise, if the property is listed then the listing broker must give you permission.
You cannot use MLS Photos and MLS Remarks without permission of the listing broker.
What about IDX?
IDX is a license to have all listings on a site, that all brokers agree to.
On sites where the number of characters is limited there is what is called the one click rule.
An example would be twitter if the link takes the consumer to a compliant page. An example of a compliant page would be an IDX page of that listing that has the listing broker disclosed.
Does KSL meet the criteria?
One you are not limited to characters, and you cannot put a clickable link in KSL, so you would need permission from the seller.
Some other basics are, you cannot lead the public to believe you are offering the home for sale, and the one click rule.
What about HUD Homes?
Yes, you can advertise HUD Homes, in fact, you are encouraged to advertise HUD Homes. But remember it is not a foreclosure, so you cannot advertise it as a foreclosure. It was a foreclosure, meaning the bank foreclosed and then HUD acquired it from the bank that foreclosed, HUD did not foreclose.