sysname is a user-defined datatype that is used in the system tables. Its definition is:
varchar(30) "NULL"
You cannot use the sysname datatype to create a column. You can, however, create a user-defined datatype with a base type of sysname. You can then use this user-defined datatype to create columns. For more information about user-defined datatypes, see “Creating user-defined datatypes”.
