ys.

<p>
The <i>value</i> parameter may be any arbitrary string which may contain
any of the following variables, which will be substituted with the
corresponding value before the script is executed:
<ul>
  <li><b>%A</b> - anonymous login password
  <li><b>%a</b> - client's IP address
  <li><b>%b</b> - bytes transferred
  <li><b>%C</b> - current working directory
  <li><b>%c</b> - connection class
  <li><b>%F</b> - transferred file as seen by client
  <li><b>%f</b> - full transferred file path
  <li><b>%g</