Actually, there’s another default type in Mochaccino, <EntryPoint>, which is used by the module containing the main function. However, this type is considered an exception, and the term “default types” excludes this type.
The default types are written in lowercase, while custom types are written in CamelCase.
Mochaccino doesn’t support null types, because the null value can be used with any type. A variable can be either null, or holding data.