The next few additions will be the various forms of "aliens" in the Orion Travelers setting.

The 4 categories are:

Gaians
Starflauna
Doomworlders
True Aliens

Although I'll go into more detail in following updates, the Fermi Paradox was generally confirmed, although the Great Filter hypothesis was replaced by the "Multiple small filters" theory (the vast majority of which happen before advanced civilization, the exception being the final filter of mass use of nuclear weapons before invention of space travel & colonization). Intelligent Advanced Civilizations are rare in the Galaxy. In fact, of this type of Alien, the "True Aliens" as most refer to them, there are only 3 known, and of those, only 1 is in the Orion spur with humans.

That species, whose self-name is unpronounceable to humans (spoken the their pheremone-based language), are reffered to by others as Tomassians, after the designation of their homeworld, 2MASS 19281982−2640123. They are the originators of the WOW! Signal detected by SETI in 1977 as a result of Tomassians scanning solar systems with X-Ray beams in 1845 CE.

The other two True Aliens are only known from the continuing SETI searches looking for signs from outside the Orion Spur, and are still too distant to interact with.

Doomworlders are sapient species from worlds doomed by one of the small filters. Generally tribal unless uplifted (intentionally or accidentally) by a Gaian race.

Starflauna are life that evolved in asteroids, comets, planetary rings, etc. Giving them access to space, but never evolutionary pressures for civilization-building capabilities. Some benign, some dangerous.

Gaians are all descended from Earth before the Diaspora. Influences range from intentional practical or cosmetic genetic engineering, uplifting of animals, to rapid evolution from environmental bottlenecks with cultures, and cultures that experimented with different social paradigms. For most stories, Gaians are "Alien enough".