(PHP 4 >= 4.0.5, PHP 5, PHP 7) Set current setting for character encoding conversion

(PHP 7) Check if code point is a letter character

(PHP 4 >= 4.0.6, PHP 5, PHP 7) Send encoded mail

(PHP 7) Make Unicode character lowercase public

(PHP 5 >= 5.3.0, PHP 7, PECL intl >= 1.0.0) Get formatter's last error code.

(PHP 5.5.0, PHP 7, PECL >= 3.0.0a1) Get the aliases of the given name

(PHP 7) Get the FC_NFKC_Closure property for a code point

(PHP 4 >= 4.0.6, PHP 5, PHP 7) Set/Get current language

(PHP 5.5.0, PHP 7, PECL >= 3.0.0a1) Get the calendar type

(PHP 5 >= 5.3.0, PHP 7, PECL intl >= 1.0.2, PHP 7, PECL idn >= 0.1) Convert domain name to IDNA ASCII