The Principality of Oertha produces a newsletter twice per year regarding the news and happenings of the Principality. The name could be considered to be derived from the meaning of the name of the Principality itself as found ias found in the original tome: "Oertha is the name for the guardian of the North (however, at this time, this is simple conjecture).
The Guardian, January A.S. XLV (2011) (PDF)(HTML)
The Eskalyan Chronicle (The Barony of Eskalya's newsletter)
The Gatekeeper (The Barony of Winter's Gate's newsletter)
The DragonTale (The Barony of Selviergard's newsletter)
The Newsletter Archive of the Principality of Oertha (Master Khevron's project)