<?php class myclass extends yourclass implements someint { function myfunc($var) { echo $var; } } $myvar = true; myfunc(&$myvar); myfunc($myvar); $this->myfunc(&$myvar); $this->myfunc($myvar); myclass::myfunc(&$myvar); myclass::myfunc($myvar); while(testfunc($var1, &$var2, $var3, &$var4) === false) { } sprintf("0%o", 0777 & $p); $foo(&$myvar); if (is_array($foo = &$this->bar())) { } Hooks::run( 'SecondaryDataUpdates', [ $title, $old, $recursive, $parserOutput, &$updates ] ); $foo = Bar(&$fooBar); myfunc($myvar&$myvar); myfunc($myvar[0]&$myvar); myfunc(myclass::MY_CONST&$myvar); myfunc(MY_CONST&$myvar); efg( true == &$b ); efg( true === &$b );