Mathematica uses its symbolic architecture to provide a convenient modular framework for generating and managing messages, both in programs and interactive sessions.
Quiet — evaluate an expression "quietly", outputting no messages
Off — globally switch off a message
On — switch on a message or a group of messages (some messages are off by default)
"Symbolics","Graphics","Compiler",... — named groups of messages
MessageName (
::) — the symbolic name for a message, assigned with
=
Message — output a named message, filling in specified elements
Check — check whether a message has been generated
MessageDialog — put up a message dialog
$MessagePrePrint — a function to apply to message arguments before printing
$Language — the default global language for messages
$MessageGroups — resettable lists of messages, mostly off by default
