Forms of Normalization

The shorthand rules of normalization are:

1. No embedded lists of unknown length.
   
2. ... implied by #3 ...
   
3. Dependence on the whole key and nothing but the key.
   
4. ... implied by #5 ...
   
5. No combined many-to-many associations.
   

The definition of an entity includes 1st normal form. (Some E-R tools support conceptual modeling of embedded entities). Thus candidate keys are required for 1NF entities.

Normalization to the 2nd degree or higher is an option of the database designer.