Requirement

UNF
(1970)

1NF
(1970)

2NF
(1971)

3NF
(1971)

EKNF
(1982)

BCNF
(1974)

4NF
(1977)

ETNF
(2012)

5NF
(1979)

DKNF
(1981)

6NF
(2003)

Primary key (no duplicate tuples)

MAYBE

✅

✅

✅

✅

✅

✅

✅

✅

✅

✅

Atomic columns (cells cannot have tables as values)

❌

✅

✅

✅

✅

✅

✅

✅

✅

✅

✅

Every non-trivial functional dependency either does not begin with a proper subset of a candidate key or ends with a prime attribute (no partial functional dependencies of non-prime attributes on candidate keys)

❌

❌

✅

✅

✅

✅

✅

✅

✅

✅

✅

Every non-trivial functional dependency either begins with a superkey or ends with a prime attribute (no transitive functional dependencies of non-prime attributes on candidate keys)

❌

❌

❌

✅

✅

✅

✅

✅

✅

✅

✅

Every non-trivial functional dependency either begins with a superkey or ends with an elementary prime attribute

❌

❌

❌

❌

✅

✅

✅

✅

✅

✅

N/A

Every non-trivial functional dependency begins with a superkey

❌

❌

❌

❌

❌

✅

✅

✅

✅

✅

N/A

Every non-trivial multivalued dependency begins with a superkey

❌

❌

❌

❌

❌

❌

✅

✅

✅

✅

N/A

Every join dependency has a superkey component

❌

❌

❌

❌

❌

❌

❌

✅

✅

✅

N/A

Every join dependency has only superkey components

❌

❌

❌

❌

❌

❌

❌

❌

✅

✅

N/A

Every constraint is a consequence of domain constraints and key constraints

❌

❌

❌

❌

❌

❌

❌

❌

❌

✅

❌

Every join dependency is trivial

❌

❌

❌

❌

❌

❌

❌

❌

❌

❌

✅