With a 00–99 PAO, read six digits per image — first pair = Person, second = Action, third = Object.

* Six digits become one scene: pairs 15/27/38 map to Person/Action/Object at one locus. *

Exactly like cards, but the "items" are 2-digit numbers. Chunk the number into sixes: 15 27 38 → Person 15, Action 27, Object 38 → one composite. Place composites along a palace and you can hold hundreds of digits with a manageable number of images. This is the standard competitive method for the "spoken numbers" and "numbers" disciplines — six digits per locus instead of one or two.

Go deeper:

• Nelson Dellis — How to create a 2-digit PAO system — building the 00–99 PAO that reads six digits per image.
• Numeric PAO (Wikipedia) — the six-digits-per-image example.

Anything reducible to your number/card items — binary (via conversion), dates, phone numbers, PINs, IDs.

If you can map information onto your existing PAO set, PAO can carry it:

• Binary — convert bits to decimal, then use the number PAO.
• Dates / years — encode the digits.
• Phone numbers, PINs, account numbers — chunk and encode as numbers.

You don't build a new system per task; you funnel everything through the one PAO you already drilled. Reuse is the point.

Go deeper:

• Mnemonic major system (Wikipedia) — how dates, PINs and phone numbers reduce to the same sounds-to-images path.