You can mute individual chat or group notifications for a specified period of time. You'll still receive messages sent to the individual chat or group, but your phone won't vibrate or make sounds when they're received.

To mute notifications:

1. Select the individual chat or group in your chats list.
2. Press Options > Mute.
3. Select the length of time you'd like to mute notifications for.
4. Press OK.

Alternatively, open the individual chat or group, then press Options > View contact or Group info > Mute notifications. Select the length of time you'd like to mute notifications for, then press OK.

To unmute notifications:

1. Select the individual chat or group in your chats list.
2. Press Options > Unmute.

Alternatively, open the individual chat or group, then press Options > View contact or Group info > Mute notifications > None.