<?php class x { public static $usedByX = 1; public static $usedByXFQN = 1; public static $unused = 2; public static $usedInside = 3; public static $usedButWrongClass = 4; function y() { self::$usedInside = 3; } } x::$usedByX = 4; \x::$usedByXFQN = 4; $x->usedButStatic = 3; y::$usedButWrongClass = 3;