UMG Developer (9/23/2010)
In addition the OrderNo column is NOT an identifier because it does not have a constraint defined on it to prevent duplicate values, or at least the DDL shown doesn't show a constraint.
Hm, not sure about this one. I tend to say that it actually IS an identifier column, because it has the IDENTITY property set. The fact that you can create an identity column without truly enforcing uniqueness is not very helpful of course.
ms-help://MS.SQLCC.v9/MS.SQLSVR.v9.en/udb9/html/e1a7a238-4953-459b-af50-50f5c2b4878e.htm
Similar quote for ROWGUIDCOL:
ROWGUIDCOL
Specifies that the column is a row globally unique identifier column. ROWGUIDCOL can only be assigned to a uniqueidentifier column, and only one uniqueidentifier column per table can be designated as the ROWGUIDCOL column. ROWGUIDCOL cannot be assigned to columns of user-defined data types.
ROWGUIDCOL does not enforce uniqueness of the values stored in the column. Also, ROWGUIDCOL does not automatically generate values for new rows that are inserted into the table. To generate unique values for each column, either use the NEWID function on INSERT statements or specify the NEWID function as the default for the column. For more information, see NEWID (Transact-SQL)and INSERT (Transact-SQL).
ms-help://MS.SQLCC.v9/MS.SQLSVR.v9.en/tsqlref9/html/a1742649-ca29-4d9b-9975-661cdbf18f78.htm
P.S. --> As already denoted by Hugo, Documentation, especially BOL, is not always a 100% correct or precise. Therefore it probably "depends" as usual.
Best Regards,
Chris Büttner