diff --git a/language/types.xml b/language/types.xml
index b8f33277ea..9b39530713 100644
--- a/language/types.xml
+++ b/language/types.xml
@@ -43,7 +43,7 @@
   </itemizedlist>
 
   <para>
-   Three compound types:
+   Four compound types:
   </para>
 
   <itemizedlist>
@@ -66,6 +66,12 @@
     </simpara>
    </listitem>
 
+   <listitem>
+    <simpara>
+     <type>iterable</type>
+    </simpara>
+   </listitem>
+
   </itemizedlist>
 
   <para>
@@ -207,6 +213,7 @@ if (is_string($a_bool)) {
  &language.types.float;
  &language.types.string;
  &language.types.array;
+ &language.types.iterable;
  &language.types.object;
  &language.types.resource;
  &language.types.null;
diff --git a/language/types/iterable.xml b/language/types/iterable.xml
new file mode 100644
index 0000000000..f21d32b323
--- /dev/null
+++ b/language/types/iterable.xml
@@ -0,0 +1,180 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- $Revision$ -->
+<sect1 xml:id="language.types.iterable">
+ <title>Iterables</title>
+
+ <para>
+  <type>Iterable</type> is a pseudo-type introduced in PHP 7.1. It accepts any
+  &array; or object implementing the <classname>Traversable</classname>
+  interface. Both of these types are iterable using &foreach; and can be used
+  with <command>yield from</command> within a <link
+  linkend="language.generators">generator</link>.
+ </para>
+
+ <sect2 xml:id="language.types.iterable.using">
+  <title>Using Iterables</title>
+
+  <para>
+   Iterable can be used as a parameter type to indicate that a function
+   requires a set of values, but does not care about the form of the value set
+   since it will be used with &foreach;. If a value is not an array or
+   instance of <classname>Traversable</classname>, a
+   <classname>TypeError</classname> will be thrown.
+  </para>
+
+  <para>
+   <example>
+    <title>
+     Iterable parameter type example
+    </title>
+    <programlisting role="php">
+<![CDATA[
+<?php
+
+function foo(iterable $iterable) {
+    foreach ($iterable as $value) {
+        // ...
+    } 
+}
+
+?>
+]]>
+    </programlisting>
+   </example>
+  </para>
+
+  <para>
+   Parameters declared as iterable may use &null; or an array as a default
+   value.
+  </para>
+
+  <para>
+   <example>
+    <title>
+     Iterable parameter default value example
+    </title>
+    <programlisting role="php">
+<![CDATA[
+<?php
+
+function foo(iterable $iterable = []) {
+    // ...
+}
+
+?>
+]]>
+    </programlisting>
+   </example>
+  </para>
+
+  <para>
+   Iterable can also be used as a return type to indicate a function will
+   return an iterable value. If the returned value is not an array or instance
+   of <classname>Traversable</classname>, a <classname>TypeError</classname>
+   will be thrown.
+  </para>
+
+  <para>
+   <example>
+    <title>
+     Iterable return type example
+    </title>
+    <programlisting role="php">
+<![CDATA[
+<?php
+
+function bar(): iterable {
+    return [1, 2, 3];
+}
+
+?>
+]]>
+    </programlisting>
+   </example>
+  </para>
+
+  <para>
+   Functions declaring iterable as a return type may also be <link
+   linkend="language.generators">generators</link>.
+  </para>
+
+  <para>
+   <example>
+    <title>
+     Iterable generator return type example
+    </title>
+    <programlisting role="php">
+<![CDATA[
+<?php
+
+function gen(): iterable {
+    yield 1;
+    yield 2;
+    yield 3;
+}
+
+?>
+]]>
+    </programlisting>
+   </example>
+  </para>
+ </sect2>
+
+ <sect2 xml:id="language.types.iterable.variance">
+  <title>Iterable Type Variance</title>
+
+  <para>
+   Classes extending/implementing may broaden methods using &array; or
+   <classname>Traversable</classname> as parameter types to
+   <type>iterable</type> or narrow return types from <type>iterable</type> to
+   &array; or <classname>Traversable</classname>.
+  </para>
+
+  <para>
+   <example>
+    <title>
+     Iterable type variance example
+    </title>
+    <programlisting role="php">
+<![CDATA[
+<?php
+
+interface Example {
+    public function method(array $array): iterable;
+}
+
+class ExampleImplementation implements Example {
+    public function method(iterable $iterable): array {
+        // Parameter broadened and return type narrowed.
+    }
+}
+
+?>
+]]>
+    </programlisting>
+   </example>
+  </para>
+ </sect2>
+
+</sect1>
+
+<!-- Keep this comment at the end of the file
+Local variables:
+mode: sgml
+sgml-omittag:t
+sgml-shorttag:t
+sgml-minimize-attributes:nil
+sgml-always-quote-attributes:t
+sgml-indent-step:1
+sgml-indent-data:t
+indent-tabs-mode:nil
+sgml-parent-document:nil
+sgml-default-dtd-file:"~/.phpdoc/manual.ced"
+sgml-exposed-tags:nil
+sgml-local-catalogs:nil
+sgml-local-ecat-files:nil
+End:
+vim600: syn=xml fen fdm=syntax fdl=2 si
+vim: et tw=78 syn=sgml
+vi: ts=1 sw=1
+-->
diff --git a/reference/var/functions/is-iterable.xml b/reference/var/functions/is-iterable.xml
new file mode 100644
index 0000000000..833afa5bb9
--- /dev/null
+++ b/reference/var/functions/is-iterable.xml
@@ -0,0 +1,100 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- $Revision$ -->
+<refentry xml:id="function.is-iterable" xmlns="http://docbook.org/ns/docbook">
+ <refnamediv>
+  <refname>is_iterable</refname>
+  <refpurpose>
+   Verify that the contents of a variable is an iterable value
+  </refpurpose>
+ </refnamediv>
+
+ <refsect1 role="description">
+  &reftitle.description;
+  <methodsynopsis>
+   <type>bool</type><methodname>is_iterable</methodname>
+   <methodparam><type>mixed</type><parameter>var</parameter></methodparam>
+  </methodsynopsis>
+  <para>
+   Verify that the contents of a variable is accepted by the
+   <type>iterable</type> pseudo-type, i.e. that it is an <type>array</type> or
+   an object implementing <classname>Traversable</classname>
+  </para>
+ </refsect1>
+
+ <refsect1 role="parameters">
+  &reftitle.parameters;
+  <para>
+   <variablelist>
+    <varlistentry>
+     <term><parameter>var</parameter></term>
+     <listitem>
+      <para>
+       The value to check
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </para>
+ </refsect1>
+
+ <refsect1 role="returnvalues">
+  &reftitle.returnvalues;
+  <para>
+   Returns &true; if <parameter>var</parameter> is iterable, &false; 
+   otherwise.
+  </para>
+ </refsect1>
+
+ <refsect1 role="examples">
+  &reftitle.examples;
+  <para>
+   <example>
+    <title><function>is_iterable</function> examples</title>
+    <programlisting role="php">
+<![CDATA[
+<?php
+
+var_dump(is_iterable([1, 2, 3]));  // bool(true)
+var_dump(is_iterable(new ArrayIterator([1, 2, 3])));  // bool(true)
+var_dump(is_iterable((function () { yield 1; })()));  // bool(true)
+var_dump(is_iterable(1));  // bool(false)
+var_dump(is_iterable(new stdClass()));  // bool(false)
+
+?>
+]]>
+    </programlisting>
+   </example>   
+  </para>   
+ </refsect1>
+
+ <refsect1 role="seealso">
+  &reftitle.seealso;
+  <para>
+   <simplelist>
+    <member><function>is_array</function></member>
+   </simplelist>
+  </para>
+ </refsect1>
+
+</refentry>
+
+<!-- Keep this comment at the end of the file
+Local variables:
+mode: sgml
+sgml-omittag:t
+sgml-shorttag:t
+sgml-minimize-attributes:nil
+sgml-always-quote-attributes:t
+sgml-indent-step:1
+sgml-indent-data:t
+indent-tabs-mode:nil
+sgml-parent-document:nil
+sgml-default-dtd-file:"~/.phpdoc/manual.ced"
+sgml-exposed-tags:nil
+sgml-local-catalogs:nil
+sgml-local-ecat-files:nil
+End:
+vim600: syn=xml fen fdm=syntax fdl=2 si
+vim: et tw=78 syn=sgml
+vi: ts=1 sw=1
+-->
diff --git a/reference/var/versions.xml b/reference/var/versions.xml
index e5632cbc26..f82bb1002d 100644
--- a/reference/var/versions.xml
+++ b/reference/var/versions.xml
@@ -22,6 +22,7 @@
  <function name='is_float' from='PHP 4, PHP 5, PHP 7'/>
  <function name='is_int' from='PHP 4, PHP 5, PHP 7'/>
  <function name='is_integer' from='PHP 4, PHP 5, PHP 7'/>
+ <function name="is_iterable" from="PHP 7 &gt;= 7.1.0" />
  <function name='is_long' from='PHP 4, PHP 5, PHP 7'/>
  <function name='is_null' from='PHP 4 &gt;= 4.0.4, PHP 5, PHP 7'/>
  <function name='is_numeric' from='PHP 4, PHP 5, PHP 7'/>