Most people use “up” for the same general concept, except for particle physicists for whom “up” is a type of quark (but only when discussing subatomic particles, not when taking the elevator – context is often vital). This is not strange (that’s a different type of quark) but a fairly usual occurance.
In any specialised community words tend to have slightly different meanings than they do in the rest of the world. This can lead to confusion, misunderstanding or merely complete incomprehension.
The otherkin community is no different. “I am an elf” does not generally mean that one just arrived from Middle Earth, have pointed ears and are immortal (unless eaten by orcs). However, as a nascient community, what it *does* mean is still somewhat undefined. As yet there is no equivalent for ‘spin’ to determine which way up to hold your elf…