Hi I don't know if this is the right place to ask this kind of question, and I hope I don't destroy the atmosphere on this forum. I just have few questions from this site: http://tetrisconcept.net/wiki/SRS, if you hover down to the tables, I just don't seem to understand the meaning of other symbols like R->2, 2->R. Can someone explain me what those symbols mean?

I understand this in this way, 0->R means rotate from 0 degrees to 90 degrees.

R->0 means from 270 degrees to 0 degrees.

The rest, I am confused. I don't know if I am dealing with it the right way. Please help. Thank you!