A user shall be the only group admin to be allowed to send messages and restrict other members to reply; allowing them to only view the message sent by the group admin.
The Restricted Groups setting is a feature available only for groupadmins. Switching it on disables all chat functionalities for non-admins from sending text messages, images and videos to recording voice messages and sharing documents or locations.
Admins, meanwhile, will be able to continue chatting as normal. Everyone else will simply have to read their messages in silence.
Non-admins who to request a word in the conversation can click on the “Message Admin” button that enables him to do so. However, the admin’s approval to the request is a must in order for the message to go through to the rest of the group.
Admins will only be able to change the setting every 72 hours, which means group members will be silenced for days at a time.
It is important to mention that this feature is still being tested by Whatsapp and will soon be available for all users. You can test it out now by signing up to the beta version of WhatsApp. Sources: http://www.independent.co.uk/ and https://www.lbcgroup.tv