Alt traders will get marked as ALT?

If you have an account that is marked as a scammer, then any of your other accounts will be marked as an alt of that account. If all of your alt accounts are clean, and you've never been tagged before on any of your accounts, then you have nothing to worry about.

Having an alt account(s), in itself, is not a crime, and there are legitimate reasons to have one or more alt accounts. Many of the staff here, myself included, have alt accounts for one reason or another. The reason some accounts are marked for "alt" is because they are alt accounts of scammers who were themselves already tagged for committing fraud. When we mark someone, we intend to warn the community not to conduct business with that person, not just that account, so if a scammer has 3 alt accounts then all 3 of those accounts will be marked when the main account is marked. If a scammer, frustrated with being banned or having nobody willing to trade with them, creates a new account, then we also tag the new account as an alt, hence why you see some accounts marked simply as "alt".