@@ -112,6 +112,23 @@ as determined by PHP's ``is_`` functions.
112112* `scalar <http://php.net/is_scalar >`_
113113* `string <http://php.net/is_string >`_
114114
115+ Also, you can use ``ctype_ `` functions from corresponding `built-in PHP extension <http://php.net/book.ctype.php >`_.
116+ Consider `a list of ctype functions <http://php.net/ref.ctype.php >`_:
117+
118+ * `alnum <http://php.net/function.ctype-alnum.php >`_
119+ * `alpha <http://php.net/function.ctype-alpha.php >`_
120+ * `cntrl <http://php.net/function.ctype-cntrl.php >`_
121+ * `digit <http://php.net/function.ctype-digit.php >`_
122+ * `graph <http://php.net/function.ctype-graph.php >`_
123+ * `lower <http://php.net/function.ctype-lower.php >`_
124+ * `print <http://php.net/function.ctype-print.php >`_
125+ * `punct <http://php.net/function.ctype-punct.php >`_
126+ * `space <http://php.net/function.ctype-space.php >`_
127+ * `upper <http://php.net/function.ctype-upper.php >`_
128+ * `xdigit <http://php.net/function.ctype-xdigit.php >`_
129+
130+ Make sure that proper `locale <http://php.net/function.setlocale.php >`_ is set before using one of those.
131+
115132message
116133~~~~~~~
117134
