The namespaces defined through this setter or through a "namespace" declaration
in one of the TypoScripts are used to resolve a fully qualified TypoScript
object name while parsing TypoScript code.
The alias is the handle by wich the namespace can be referred to.
The namespace is, by convention, a package key which must correspond to a
namespace used in the prototype definitions for TypoScript object types.
The special alias "default" is used as a fallback for resolution of unqualified
TypoScript object types.
