ST205 Engine Replacement : Sticker on Timing Belt Cover, A1, L1, T1, T7 stickers amongst others Options

[Jeebus]

Hey, just wondering whether anyone can shed some light on these stickers found on the timing belt cover, and what they mean. I want to make my engine swap as hassle free as possible, so getting a 3rd gen 3SGTE from a SW20 MR2 is out of the question, but maybe a 4th gen 3SGTE from a ST215 is still possible?

The stickers I've noticed:

3rd Gen 3SGTE - 93~94 SW20:
P1, Q1, Y1, Y5

3rd Gen 3SGTE - 94+ ST205 Celicas
A1, L1, T1, T7

4th Gen 3SGTE - 98+ ST215 Caldinas
N2, N4

This post has been edited by Jeebus: Jan 25, 2016 - 8:19 PM