SELECT
    object_name =
        OBJECT_NAME(ac.object_id),
    ac.name,
    ac.column_id,
    ac.system_type_id,
    ac.user_type_id,
    ac.max_length,
    ac.precision,
    ac.scale,
    ac.collation_name
FROM sys.all_columns AS ac
WHERE ac.object_id = OBJECT_ID('sys.messages');

EXEC sys.sp_describe_first_result_set
    N'SELECT ERROR_MESSAGE();';

Msg 11541, Level 16, State 1, Procedure sys.sp_describe_first_result_set, Line 1 [Batch Start Line 18]
sp_describe_first_result_set cannot be invoked when SET STATISTICS XML or SET STATISTICS PROFILE is on.

DECLARE
    @error_message nvarchar(4000) =
        REPLICATE('A', 8000);

EXEC sp_addmessage
    50001,
    10,
    @error_message;

SELECT
    m.*,
    l = LEN(m.text),
    dl = DATALENGTH(m.text)
FROM sys.messages AS m
WHERE m.message_id = 50001;

EXEC sp_dropmessage
    50001;

  create procedure sys.sp_addmessage
	@msgnum int = null,				-- Number of new message.
	@severity smallint = null,		-- Severity of new message.
	@msgtext nvarchar(255) = null,	-- Text of new message.
	@lang sysname = null,			-- language (name) of new message
	@with_log varchar(5) = null,	-- Whether the message will ALWAYS go to the NT event log
	@replace varchar(7) = null		-- Optional parameter to specify that
									-- existing message with same number should be overwritten.

PRINT CASE WHEN N'½' COLLATE Latin1_General_100_CI_AS LIKE N'[0-1]' THEN 1 ELSE 0 END;

PRINT CASE WHEN N'½' COLLATE Latin1_General_100_CI_AS LIKE N'[0]' THEN 1 ELSE 0 END;
PRINT CASE WHEN N'½' COLLATE Latin1_General_100_CI_AS LIKE N'[1]' THEN 1 ELSE 0 END;