No confusion, but I just think it's a bit clumsy to have to write "spell level" in rulesy stuff when you work on metamagicish things.
Personally, I call spell slots "valences" and each spell level has a name, used in-character by wizards and all sorts of mystics. Name taken from the abaccus stones (called apices, singular apex) of Pope Sylvester II (a.k.a. Gerbert of Aurillac). The original names are sipos (0), igin (1), andras (2), ormis (3), arbas (4), quimas (5), calctis (6), zenis (7), temenias (8) and celentis (9). It seems the names originated from that latin poem:
ordine primigeno sibi nomen possidet igin
andras ecce locum previndicat ipse secundum
ormis post numerus non compositus sibi primus
denique bis binos succedens indicat arbas
significat quinos ficto de nomine quimas
sexta tenet calcis perfecto munere gaudens
zenis enim digne septeno fulget honore
octo beatificos temenias exprimit unus
terque notat trinum celentis nomine rithmum
hinc sequitur sipos est qui rota namque vocatur
It's unclear where the names themselves come, though some of them sounds semitic or arabic. Anyway, I found them to be perfectly
arcane names for numbers -- perfect for naming spell levels in the background of my homebrew. I've twisted them a bit so that they would all end in -is (sepis, igis, andris, ormis, quamis, etc.) to make it look like there was a convention behind the names, and transvalent spells (epic spells, sometimes referred to as tenth-level spells) are simply Is -- raw magical potential.
