MSSQL2000: UDT and Nullability

When you create a UDT with the sp_addtype sproc, you can control the Nullability. Later, when you create a table using that UDT as a column's data type, you can also set the nullability. How do these two nullabilies relate to each other? (IE - can I make all my UDT's 'NOT NULL', and then later make a column usings this type allow nulls on table creation?)

Thanks.

Whatever you specify as the UDT, it doesn't seem to make any difference when creating the table (just the default).

Okay, as I like to script everything explicitly as "NOT NULL" except when it needs to be "NULL". Thanks. I'm debating whether to use UDTs at all anyway.