We have replaced the old chat box (CB) with the new Shoutbox (SB). Shoutbox is not available to New Mobilarians.
And it still located at forum index page below the forum list.

We can now PM a particular user in the Shoutbox by clicking their username then select Send Private Message. This will
open a new tab in the Shoutbox where you could talk to that user privately. Shouts will have the [PM] indicator to let
you know that it is a private message and only you can see it.

The tab labelled User Tags is used in conjunction with User Tagging. If someone refers to you in a post (by using
the @username; code) you will be notified in the User Tags tab of the Shoutbox. This is particularly convenient to users
who hang out at the Shoutbox a lot and want to be notified when someone tags them in the forums without reloading
the page or enabling the desktop notification.

The following commands can also be used for purposes specified below.

/ignore username = hide all shouts of a particular user (Staff members cannot be ignored)
/unignore username = show all shouts of a particular user you previously ignored
/me text - refer to yourself in third person when posting a shout