Chatango refers to it as the "@mention feature" . Others refer to it as "tagging", "ping/ing", or just "@" etc.
It's only effective in HTML5 chatrooms and it's purpose is to get a user's attention or direct a message towards a specific user by @mentioning their username. Multiple usernames can be @mentioned in one message as well. Once you're @mentioned, you'll hear a ping and the @mention will be in bold (example: @username), the user who @mentioned you will have a yellow channel to denote that person has mentioned you, and you'll see your chatroom tab displaying the username that @mentioned you.
- @mentioning doesn't have to be typed out. You can simply click a user's message to @mention them.
- There's no possible way to completely disable the @mention feature in HTML5 however the ping can be muted along with all messages in the chatroom.
A message quote that's been highlighted in yellow/gold. A user can highlight a quote from another user and send it as part of their own message. You simply highlight all or parts of a message then click the message. It'll display the highlighted quote in your text box. Once you send the message, it'll mention the user and display the quote you highlighted in their message. Examples in the images.