Talk:Pets Unlock Codes
I've found other similiar codes (ALL begining in ZZZ11ZZ) for Spanish "Los Sims 2 Mascotas". You could get it here:
They are categorized too for better pourpose.
As you say, there is some pattern to extract them and the first eight digit patterns and last six digit patterns mark in some manner localization version. Some people found for example: KMKYB1Axxxxxxx
Many of the codes on that page are identical to the ones shown here - meaning they took them from this page as codes are unique to individual games. HystericalParoxysm