what is Boyce-Codd Normal Form (BCNF)?

Boyce-Codd Normal Form (BCNF) is one of the forms of database normalization. A database table is in BCNF if and only if there are no non-trivial functional dependencies of attributes on anything other than a superset of a candidate key. BCNF is also sometimes referred to as 3.5NF, or 3.5 Normal Form.