On a dashboard widget, open its actions menu and select Conversations.
In the Conversations panel, select New Conversation.
Write your comment. To bring someone in, type their name and pick them from the suggestions.
Send it.
[Image: The Conversations panel on a widget with a comment that mentions a colleague]
The menu shows how many conversations a widget has, for example Conversations (2).
People can only see a conversation if they can see the dashboard it's on.
Notifications
The bell at the top of the page shows your notifications, with the number unread. Open it to see them, and select Mark all as read to clear them.