Welcome to my pen!
Characters are grouped into posts based on their default world setting. Characters in the same post do not necessarily know one another, but they do exist in the same world together.
Every post has a note at the top describing the world the characters live in and the technology and magic levels they would be familiar with as a baseline for roleplays.
Most characters are available both in pet form or another form as described in their bio. They are treated as distinct, but otherwise identical to one another. (Like parallel universes.)