Seeing the $_REQUEST[] and it is a matrix that has the content of $_GET, $_POST and $_COOKIE, I think this can be used maliciously into the script. i.e.: request1.php <?php setCookie("name","alejandro"); echo "<script>location.href='request2.php'</script>"; ?> In this case, I'm setting the variable 'name' with value 'Alejandro', then redirects to request2.php request2.php ?php print_r($_COOKIE); echo "<br>"; print_r($_REQUEST); echo "<br>"; if(@$_REQUEST['name'] == "admin"){ echo "I am admin"; }else{ echo "You can not see this page"; } ?> Here's the problem. The variable called 'name' is into REQUEST context, and this is accessible by GET and POST methods, and it is accessible by the COOKIE matrix as well. In this case, use Request is unsafe because I can change the variable called 'name' via GET method and it's give me access as admin. Mi question is: I do not see the good practice of using COOKIE values into of REQUEST, what I mean is that it can become in a programming bug. Also I could not fin answers anywhere else. thoughts? Thanks!