Why not use number names? O=0 I=1 Z=2 L=3 T=4 S=5 J=6

That could work for O, I, Z, and S; maybe L could be 7, but not the other tetriminoes. It's best to use letters. 108.66.233.243 11:26, 1 August 2017 (PDT)

That was 2014 edit. I was dumber at that time. Piotr Grochowski 11:43, 1 August 2017 (PDT)