|03:53 am - The principle of cautious design|
Whenever we are faced with a choice between two designs, and the first design is upward compatible with the second (i.e. the first design is more restrictive, and implementing design two would not affect functionality provided by design one), and the full impliciations of the second design are not yet known, the first design choice is recommended.
Formulated by C.J. Date in "Relational Database: Writings 1989-1991"