1NF restriction :
1. Value should be atomic (Unique).
2NF restriction :
1. All the non-prime attributes should be fully functionally depended on each candidate key.
3NF restriction :
1. There should not be any transitive relation or dependency among non-prime attributes.
BCNF or 3.5NF restriction :
1. Part of primary key should not be fully functionally dependent on non-primary key.