diff --git a/system/language/english/form_validation_lang.php b/system/language/english/form_validation_lang.php
index e5ef09e..a66e192 100644
--- a/system/language/english/form_validation_lang.php
+++ b/system/language/english/form_validation_lang.php
@@ -65,3 +65,4 @@
 $lang['form_validation_greater_than']		= 'The {field} field must contain a number greater than {param}.';
 $lang['form_validation_greater_than_equal_to']	= 'The {field} field must contain a number greater than or equal to {param}.';
 $lang['form_validation_error_message_not_set']	= 'Unable to access an error message corresponding to your field name {field}.';
+$lang['form_validation_in']		= 'The {field} field must be one of: {param}.';
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index 8192245..e81216e 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -1449,6 +1449,20 @@
 	// --------------------------------------------------------------------
 
 	/**
+	 * Value should be within an array of values
+	 *
+	 * @param	string
+	 * @param	array
+	 * @return	bool
+	 */
+	public function in($value, $list)
+	{
+		return in_array($value, explode(',', $list), TRUE);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Is a Natural number  (0,1,2,3, etc.)
 	 *
 	 * @param	string
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index a22b94f..0f89077 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -350,6 +350,7 @@
       -  Removed method ``is_numeric()`` as it exists as a native PHP function and ``_execute()`` will find and use that (the **is_numeric** rule itself is deprecated since 1.6.1).
       -  Native PHP functions used as rules can now accept an additional parameter, other than the data itself.
       -  Updated method ``set_rules()`` to accept an array of rules as well as a string.
+      -  Added support for ``in`` method that test if a given value is within a given list.
       -  Fields that have empty rules set no longer run through validation (and therefore are not considered erroneous).
       -  Added rule **differs** to check if the value of a field differs from the value of another field.
       -  Added rule **valid_url**.
diff --git a/user_guide_src/source/libraries/form_validation.rst b/user_guide_src/source/libraries/form_validation.rst
index f964965..4ba3a33 100644
--- a/user_guide_src/source/libraries/form_validation.rst
+++ b/user_guide_src/source/libraries/form_validation.rst
@@ -961,6 +961,7 @@
                                      not numeric.
 **less_than_equal_to**    Yes        Returns FALSE if the form element is greater than the parameter value,                        less_than_equal_to[8]
                                      or not numeric.
+**in**                    Yes        Returns FALSE if the form element is not within a predetermined list.                         in[red,blue,green]
 **alpha**                 No         Returns FALSE if the form element contains anything other than alphabetical characters.
 **alpha_numeric**         No         Returns FALSE if the form element contains anything other than alpha-numeric characters.
 **alpha_numeric_spaces**  No         Returns FALSE if the form element contains anything other than alpha-numeric characters