All user login account names must satisfy the following rules:
<ul>
<li>may contain digits 0..9, the lower-case letters a..z and
  the special character "-".</li>
<li>must begin with a lower-case letter a..z.</li>
<li>must not be shorter than 3 or longer than 8 characters.</li>
</ul>

<em>SLAC reserves the right to block account names that are deemed inappropriate.</em>
<p>
Here is a regular expression that matches valid account names:
<code>^[a-z][a-z0-9\-]{2,7}$</code>