Being relatively new to EL&U, I have more than occasionally come across an acronym (in a comment or answer) I did not know how to translate! OP is but one of them. To this day, I'm not sure what OP stands for (original poster?).
Does a list of acronyms commonly used by contributors to the site actually exist? If so, where is it? If not, what would it take to provide one to new contributors? It seems to me to be a logical addition to FAQ (i.e., frequently asked question). [See, I kindly provided a "translation" for an acronym. It did, however, take me 2.6 seconds to do it. What a wastrel of time I am!] A couple acronyms I came across on the site today are SO and CSS.
As a student of law, I am more than a little familiar with the need for specialists in any given field or discipline to speak in jargon and code to save time, the assumption being that whoever is reading "insider information" should know what a given acronym stands for. That assumption, however, is not always justified.