if "(foo)" let x = "(foo)" endif ( ) let x = ( "( )" ) let y = "(" \ . ")" "(" ) \ . ")" let z = ( '( ' ) . ' )' let a = " if endif " *cpo-M* M When excluded, "%" matching will take backslashes into account. Thus in "( \( )" and "\( ( \)" the outer parenthesis match. When included "%" ignores backslashes, which is Vi compatible. let b = '\( \)' let c = "\\( \\)" let d = "( \\( )" . "\\( " . '\( \)' . "\\)"