In plurality, a source refers to some material that a headmate came from.
Headmates with sources are typically introjects, although this isn't necessarily the case.
Headmates of any origin can have sources, their source is distinct from the method that they came into being.
Related Terms[]
There are several more specific terms that encompass different types of sources. This includes fictional works (fictives), other people (factives), characters created by a member of the system (mostives), and others.