My compliments to David Poole for his last comment on the topic.

I also would like to add the following. UDT similar to ty_int does not serve the purpose of enforcing domain integrity. My preference is UDT similar to udt_user_id, udt_yes_no_bit, udt_phone, udt_address, udt_client_code, etc. In other word, UDT should be business oriented.

Any opinions?

Michael