capndurk: No, at_type doesnt return the id. It identifies the type of message.
Code:
at_notice,
at_console, // same as at_notice, but forces a ConPrintf, not a message box
at_aiconsole, // same as at_console, but only shown if developer level is 2!
at_warning,
at_error,
at_logged // Server print to console ( only in multiplayer games ).
And if your using this in CS then it should always be at_logged