Database Normalization

Database Design - Normalization
http://en.wikipedia.org/wiki/Relational_database_design#Normalization

Database Normalization
http://en.wikipedia.org/wiki/Database_normalization

Denormailization
http://en.wikipedia.org/wiki/Denormalization

internationalization (i18n)

Locale = Language code (ISO-639) + Country code (ISO-3166)
e.g. zh_TW