The following description of the dbcc check command should be included in Reference Manual: Commands.
dbcc upgrade_object( {dbid | dbname}, { compiled_object_name | "view" | "procedure" | "default" | "rule" | "default" | "trigger" }, [ "force" | "check" ] )
check – checks syntax for the specified compiled_object in syscomments in the specified database. Does not raise errors on occurrences of select.
check is used to detect syscomments text corruption which was caused by Adaptive Server defects that occured before the upgrade. This syscomments text corruption is serious because it causes upgrade to fail.
If any error is reported by dbcc upgrade_object with check option, you must drop and re-create the compiled_object.