Description:
------------
It's stated in http://php.net/manual/en/language.oop5.paamayim-nekudotayim.php that "Two special keywords _self_ and _parent_ are used to access properties or methods from inside the class definition", but there's also 3rd keyword which is not mentioned - "static".

Test script:
---------------
<?php

    header('content-type: text/plain');
    
    class ParentClass {

        const property = 'parent';

        public function getPropertySelf() {
            // use 'property' const of ParentClass
            return self::property;
        }

        public function getPropertyStatic() {
            // use 'property' const of called class
            return static::property;
        }

    }

    class ChildClass extends ParentClass {
        const property = 'child';
    }

    $obj = new ChildClass();
    var_dump($obj->getPropertySelf()); // string(6) "parent"
    var_dump($obj->getPropertyStatic()); // string(5) "child"