database error msgs

Is there a reference that describes error messages?
On line Books does not seem to contain error listings. Still using sequel 7.I generally go to Google and type SQL Server and then cut and past the error code and look for the first microsoft link.|||Select * from sysmessages
order by 1,2

(do as i say not as i do)

Books Online {System Error Messages}

ps does anyone know the significance of the DLevel col in sysmessages
it contains the numbers 0 1, 2, 4, 128
the internet\microsoft says that it's for future use. but my system seems to be using that col now... haw haw haw... :D|||This column is a bit-based smallint that contains severity and "loggability" (my word, copyright rdjabarov all rights reserved) of a message.|||This column is a bit-based smallint that contains severity and "loggability" (my word, copyright rdjabarov all rights reserved) of a message.

severity is already a col in sysmessages why have it twice
do i smell smoke being blown behind me?|||You may, but since it's bit-based (&) value, - it's taking into account the severity column to come up with the value.