Orientation

A tetromino's orientation, with regards to Tetris refers to the different ways that tetromino can exist after rotations.

Normally all the tetrominoes have a total of nineteen orientations, but probably to make things more symmetric, newer games add six orientations: two for S, Z, and I. Adding 3 more orientations for O can become 2017/2018 standard.

Orientations can be described either by the way they point (especially for T, which at least one reviewer has compared to a finger gesture (link --ages 30+, contains sex references, nsfw)) or by the way the longest flat side faces.