[According to the PRMIA study guide for Exam 1, Simple Exotics and Convertible Bonds have...

A quanto is any instrument in which one asset is a foreign currency. Examples include any option on a foreign currency asset with the strike price in foreign currency, and an option on a foreign currency asset with the foreign currency risk hedged.

Correlation products refer to credit products on a basket of credits. Options on options represent an option to buy or sell an option in the future, and they are not 'quantos'. Similarly, not every two asset instrument is a quanto unless one of the two assets is a foreign currency.