There is a lot of information about the structure of US phone numbers here, and while general information is good to set up the joke, the specifics can be left to the wikipedia article. Specifically, all the talk of how exchanges are numbered and long distance charges is utterly irrelevant to the strip, and the information about choosing custom numbers is relevant only to the title text (and takes about one line to explain). The meat of the joke is that area codes used to be location-based but rapidly became more flexible around 2005, resulting in that rather arbitrary meaning today, yet this is mentioned almost casually in just one sentence near the end. I will trim and reorder the article so that it's more relevant to the comic shortly, unless there are objections. - jerodast (talk) 11:01, December 3, 2012 Quite a few explanations are like that. People add things that seem relevant to them, but don't really help explain the comic. If you look at most of the explanations past the 1050 mark, quite a few of them aren't perfect. If you want to tighten them up, by all means do so. Davidy22[talk] 00:39, 4 December 2012 (UTC) I trimmed a lot of unnecessary information from the explanation, because it had nothing to do with explaining the joke of the comic. For those parties looking for more information on phone numbering plans, here is what I removed: The middle digit of the area code was originally always 0 or 1 to allow mechanical dialing circuits to identify the sequence as an area code or not. The next three digits are the exchange number (the middle digit being always 2 or higher), and the final four digits are typically random. Business customers frequently could pay a premium for a specific number (if available), either to spell a brief slogan, or for easy memorization. The prevalence of digitally controlled dialing allowed the restrictions on digits in area codes and exchanges to be relaxed, suddenly making many new area codes and exchanges available. According to the North American Numbering Plan, currently: The first 3 digits (Area Code) can be [2-9][0-9][0-9], the next 3 digits (Exchange) can be [2-9][0-9][0-9], and the final 4 digits (Subscriber Number) can be [0-9][0-9][0-9][0-9]. There are some rules for area code exceptions or reserved numbers though. Specifically, X11 codes are not valid as area codes (e.g. 411, 911, etc...) and Xyy (repeated last 2 digits) codes are reserved for special use area codes (e.g. toll-free/freephone 800, 888, etc..). - jerodast (talk) 17:44, 22 December 2012