For the obsessively curious, there's a lot of interesting (and apparently authoritative) information about U.S. and Canadian phone-number standards at NANPA, the North American Numbering Plan Adminstration. It covers arcana such as the so-called N11 numbers (911, 411, etc.), potentially valid area codes (/2-90-80-9/, except /\d11/, /37\d/, and /96\d/), vertical services codes (112?\d\d or \*2?\d\d), and so on. It even alludes to what will happen when North America eventually moves to 11-digit phone numbers (i.e., 4-digit area codes). Now there's a scary thought for anyone who's been writing phone-number validation code that assumes a 3-3-4 format.

        $perlmonks{seattlejohn} = 'John Clyman';

In reply to Re: Re: Phone reg expression by seattlejohn
in thread Phone reg expression by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.