It is called Do Not Disturb. The Do-Not-Disturb service allows MTN,ETISALAT,AIRTEL, and GLO customers to opt out of receiving promotional messages for 3rd Party services (Bulk SMS, VAS promos, etc.). To opt out of the service, you will need to text the word "ALLOW" for MTN, GLO, AIRTEL and "START" for ETISALAT to the short code 2442 . To opt-out is free. To check status, you will need to text the key word STATUS to 2442. Simply text HELP to the short code 2442 to find out more. To unsubscribe from 'Do Not Disturb' (DND), Text "STOP" for MTN, ETISALAT, AIRTEL and "CANCEL" for GLO to 2442. Nigerian Communications Commission (NCC) has directed all Telecommunications Company (MTN, GLO, Airtel, Etisalat, etc.) to allow existing subscribers to opt-in to receive SMS on Telemarketing, including but not limited to Value Added Services, e.g. flight schedule, weather forecast etc. in conformity with Part 111, section 20 (2) of CCPR, while consent of new subscribers will be sought to opt-in at the beginning of the contract.