```php
function link_back($blacklist = array())
{
$parameters = split("&", $_SERVER['QUERY_STRING']);
$uri = array_shift(split("\?", $_SERVER['REQUEST_URI']));
$index = 0;
foreach($parameters as $parameter)
{
$parameter = split("=", $parameter);
$name = $parameter[0];
$value = $parameter[1];
if(in_array($name, $blacklist))
{
unset($parameters[$index]);
}
$index++;
}
if(count($parameters) > 0)
{
$parameters = "?".join("&", $parameters);
}
else
{
$parameters = '';
}
return $uri.$parameters;
}
```
Usage:
```php
# URI is /wow_amazing_code?not_wanted=23&wanted=1
echo link_back(array('not_wanted')); # prints out /wow_amazing_code?wanted=1
```