@ <p>The settings on this page are intended to help site administrators
  @ defend the site against robots.
  @
  @ <form action="%R/setup_robot" method="post"><div>
  login_insert_csrf_secret();
  @ <input type="submit"  name="submit" value="Apply Changes"></p>
  @ <hr>
  @ <p><b>Do not allow robots access to these pages.</b><br>
  @ If the page name matches the GLOB pattern of this setting, and the
  @ users is "nobody", and the client has not previously passed a captcha
  @ test to show that it is not a robot, then the page is not displayed.
  @ A captcha test is is rendered instead.
  @ The recommended value for this setting is:
  @ <p>
  @ &emsp;&emsp;&emsp;<tt>%h(robot_restrict_default())</tt>
  @ <p>
  @ The "diff" tag covers all diffing pages such as /vdiff, /fdiff, and 
  @ /vpatch.  The "annotate" tag covers /annotate and also /blame and
  @ /praise.  The "zip" covers itself and also /tarball and /sqlar. If a
  @ tag has an "X" character appended, then it only applies if query
  @ parameters are such that the page is particularly difficult to compute.
  @ In all other case, the tag should exactly match the page name.
  @
  @ To disable robot restrictions, change this setting to "off".
  @ (Property: robot-restrict)
  @ <br>
  textarea_attribute("", 2, 80,
      "robot-restrict", "rbrestrict", robot_restrict_default(), 0);

  @ <hr>
  @ <p><b>Exceptions to anti-robot restrictions</b><br>
  @ The entry below is a list of regular expressions, one per line.
  @ If any of these regular expressions match the input URL, then the
  @ request is exempt from anti-robot defenses.  Use this, for example,
  @ to allow scripts to download release tarballs using a pattern
  @ like:</p>
  @ <p>
  @ &emsp;&emsp;<tt>^/tarball\\b*\\b(version-|release)\\b</tt>
  @ <p>The pattern should match against the REQUEST_URI with the
  @ SCRIPT_NAME prefix removed, and with QUERY_STRING appended following
  @ a "?" if QUERY_STRING exists.  (Property: robot-exception)<br>
  textarea_attribute("", 3, 80,
      "robot-exception", "rbexcept", "", 0);

  @ <hr>
  addAutoHyperlinkSettings();

  @ <hr>
  entry_attribute("Anonymous Login Validity", 11, "anon-cookie-lifespan",
                  "anoncookls", "840", 0);
  @ <p>The number of minutes for which an anonymous login cookie is valid.