Self-trading prevention: 

If a member wish to prevent trading between two or more portfolios within the same company, they can apply this restriction by sending an email to and provide a list of portfolios that should not cross match. Example:

Portfolio Prevent from matching with portfolio: 
example_portfolio1             example_portfolio2, example_portfolio3
... ...

Once restrictions are added by our support, you need to re-login to apply the changes. If you are about to trade between two portfolios where you applied self-trading restriction you will get the below warning:

In cases where you or another market participants perform a self trade, the trade price will be flagged with a star "*" in the ticker.. 

This is further explained here: