Both a specific term and a general concept.
- The Eternal War is the term used in The Colour Of Death for a million-year long conflict between "the crustacean races of Aldebaran and the winged races of the Hyades".
- As a general concept, the idea of a recurring military conflict fought down the ages and/or across different timelines in connection with the Yellow Sign has appeared in the stories of DJ Tyrer, such as News and Coming Home.