Glossary · Trading and execution
A do-not-trade flag marks an account or a security as excluded from automated trading, usually because of a client instruction, a pending transfer or a known restriction.
The important property is where the flag is enforced. A flag honored by the person running the rebalance is a reminder; a flag honored at the order itself is a control.
Questions this did not answer? Ask them directly — that is what the twenty minutes is for.