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.