Identities

Hloch is Ythrian by species, Avalonian by planet of origin and again Ythrian in interstellar politics because Avalon belongs to the Domain of Ythri. By these criteria, Tabitha Falkayn is human, Avalonian and Ythrian. She identifies as Ythrian when speaking to the captured Terran, Philippe Rochefort. Tabitha's ancestor, David Falkayn, was human and Hermetian and Hermes was then independent. David Falkayn's employer, Nicholas van Rijn, was human, Terrestrial and Solar. 

During the Terran War, all Avalonians, both human and Ythrian, are anti-Terran. However, the term, "Terran," can also be applied to species:

"This is the tale, told afresh, of how Avalon came to settlement and thus our choth to being. This is the tale as told not be Rennhi and those on whom she drew for the Sky Book, but by Terrans who walk the earth."

-Poul Anderson, INTRODUCTION WINGS OF VICTORY IN Anderson, The Van Rijn Method (Riverdale, NY, December 2009), pp. 75-77 AT p. 77.

The Sky Book is told by Ythrians; the Earth Book by human beings.