What is DND (Do Not Disturb) message?

A DND setting prohibits companies from communicating with a customer that has specifically requested not to receive messages or during periods that the customer has specifically requested not to be sent messages. In some countries a user can register their number for a DND directory to ensure that they will not receive any promotional or marketing messages. In many countries, local regulations forbid the sending of non-essential messages during weekends, holidays and after working hours on weekdays.