Penn State football/Beaver stadium question?

I have tickets for the upcoming PSU/BAMA game, I have never been to a penn state game before. I don't know how the seating works. The tickets I got are section EC row O...I see where EC is but what exactly is row "O"? Other seats in that section and others say section EC or EB or EH but will have like row 31, or 30, or 12, etc! So why does my row have a letter and not a number? Anyone that has been to a PSU game at Beaver stadium, is section EC row O, or for that matter section EC good seats? They like alright. Thank you