src/PEAR/Task/Postinstallscript/rw.php
function addParamGroup($id, $params = false, $instructions = false)
    {
        if ($params && isset($params[0]) && !isset($params[1])) {
            $params = $params[0];
        }
        $stuff =
            array(
                $this->_pkg->getTasksNs() . ':id' => $id,
            );
        if ($instructions) {
            $stuff[$this->_pkg->getTasksNs() . ':instructions'] = $instructions;
        }
        if ($params) {
            $stuff[$this->_pkg->getTasksNs() . ':param'] = $params;
        }
        $this->_params[$this->_pkg->getTasksNs() . ':paramgroup'][] = $stuff;
    }
function addParamGroup($id, $params = false, $instructions = false)
    {
        if ($params && isset($params[0]) && !isset($params[1])) {
            $params = $params[0];
        }
        $stuff =
            array(
                $this->_pkg->getTasksNs() . ':id' => $id,
            );
        if ($instructions) {
            $stuff[$this->_pkg->getTasksNs() . ':instructions'] = $instructions;
        }
        if ($params) {
            $stuff[$this->_pkg->getTasksNs() . ':param'] = $params;
        }
        $this->_params[$this->_pkg->getTasksNs() . ':paramgroup'][] = $stuff;
    }
add a simple <paramgroup> to the post-install script

Order is significant, so call this method in the same
sequence the users should see the paramgroups.  The $params
parameter should either be the result of a call to {@link getParam()}
or an array of calls to getParam().

Use {@link addConditionTypeGroup()} to add a <paramgroup> containing
a <conditiontype> tag
@param string $id <paramgroup> id as seen by the script
@param array|false $params array of getParam() calls, or false for no params
@param string|false $instructions