What is the Dominic System, and how does it compare to PAO?

Dominic O'Brien's method: each 2-digit number maps to a Person (via letter-initials) plus that person's Action — essentially PAO without the Object.

* Dominic O'Brien, whose Person-Action system pairs digits into people and their signature acts. — djbrubru, CC BY-SA 4.0, via Wikimedia Commons. *

In the Dominic System, digits become letters (1=A, 2=B, … a fixed scheme), the letter-pair gives a person's initials (e.g. 15 → "AE" → Albert Einstein), and each person has a signature action. You combine two numbers as person of the first + action of the second. So it's a Person-Action (2-part) system — a close cousin of PAO that drops the Object slot, trading a little compression for simplicity.

Go deeper:

• Dominic system (Wikipedia) — the initials-to-person-plus-action mechanic and its contrast with the Major.
• Dominic O'Brien (Wikipedia) — the 8x World Memory Champion who devised it.