Source

Roughly 3% of all people born are born as sources. Natural conduits of light or dark energy. This power is observable at the earliest by the age of four or five, expanding into their full capabilities by the mid-teen years. Typical examples of this power are low and middling in power, able to channel their inborn ability at the cost of exhaustion and effort.
The rarest individuals, 1/1000 sources are considered arch sources. These individuals have an unnaturally high ability to channel source energy as well as a lessened physical and psychological strain from doing so. 
Sources cannot permanently enchant objects, as this was a technique lost during the Forlorn Era. Sources can however temporarily charge items and prevent the further loss of their charge, but often at extreme effort and exhaustion. Sources can channel their powers in a variety of ways, not the least of which are rune magic, pure channeling, spellsong, and object channeling. 
The same organizations that attempt to recruit or abduct (depending on the nature of the organization) channelers act the same way toward sources, albeit with much more zeal. A source is an extremely valuable asset to any organization, though the same everyman fears and rumors towards channelers apply to sources as well. 
Additionally, sources are sought by kingdoms, both as an asset and due to the fact that an untrained source can be a force of absolute destruction, especially during a particularly emotional episode.