MemeMachineGo!

A Geek Code for multiple personalities: the Multiple Code.

Number (N*)

The number of (known) people who make up your system.

N---! Huh? There's only one (1) to this body!
N--- Two (2) to Three (3)
N-- Four (4) to Ten (10)
N- Eleven (11) to Twenty (20)
N Twentyone (21) to Fifty (50)
N+ Fiftyone (51) to Sixty (60)
N++ Sixtyone (61) to Eighty (80)
N+++ Eightyone (81) to One Hundred (100)
N++++ One Hundred (100) to One Thousand (1,000)
N++++! Over One Thousand (1,000+)
N~ Not one, not many -- mid-continuum.
N? Darned if we know!

The other parameters get much stranger from a singleton's perspective, covering the species of the personalities, which can range from human to familiar animal to dinosaur to alien to vampire, the worlds the personalities exist in when they're not in the body, and how the personalities came to share the body (which offers lots more choices than splitting.)

It really makes me feel I should be doing more with my brain.

I found this on Astraea's Multiplicity Resources, where there's lots more fascinating stuff. I found that on Matt Ruff's Multiplicity Links page, from his Set This House in Order page.

And I finished the book. It is wonderful. Read the excerpt. Buy the book. Lose sleep finishing it.