Using contract security, you can control which users are allowed access to which contracts. If a user is denied access to a contract, they will be unable to enter transactions to the contract, report or enquire on it, maintain it, and so on.
The contract will not appear on their lookups, and if they enter the contract code, Coins ERP+ issues a message informing them that they are not allowed to access the contract.
Access is governed by the control field, which can be the contract code, one of the other validated fields, such as contract location, or any one of the four analysis sets.