So many phases

Pharmaceutical products are tested in clinical trials, organized as phases, and I never tire of seeing all the different forms used to refer to those phases in running text, tables, figures, and line art. It's often a calculus of variation, even in a single project, especially if the text runs over 100 pages.

How many different ways could phase 1 be written in running text, tables, figures, and line art? Here's a menu of what I've seen in 6 years:

Phase 1, phase 1, Ph-1, Ph1, P 1, P1, Phase I, phase I, Ph I, PhI, P I, PI

That last one is really nasty because PI is a common abbreviation in pharmaceuticals for something entirely unrelated to clinical trial phases. It shouldn't be used, ever, to mean phase 1 but it is. Occasionally. The writer can't help it, sometimes, deadlines being drop dead and all.

Inevitably, any of those 12 possibilities listed above get tangled up in a typo or two (or 10)—especially if the text runs over 100 pages. The writer means to type phase 1, for example, but types phase1 instead. Considering that there's 4 phases, we're talking about nearly 50 possible representations (without typos).

AMA has a very simple rule: lower-case phase + Arabic numeral in running text, and any reasonable abbreviation will do for tables and figures as long as its applied consistently.