Where is the add comment link? What is O.Q.?

ReRe, ifixit is a bit different than most other forums. Here you have the chance to ask your own personal question, and receive an individualized answer. You would use the "Ask a question" tab to the right of the screen which will take you here http://www.ifixit.com/Answers/Ask/iFixit Then you ask your question. If you post a question either as an answer or a comment to someone elses question, it will get lost and you most likely will not get an answer. This is done so that the focus is on answering the original question only. O.Q. possibly means "other question" if you have posted more than one question. The add comment link is the light blue link just above the answers. Hope this explains it.