diff --git a/cake/libs/view/helpers/form.php b/cake/libs/view/helpers/form.php
index 9c702598f..723546e46 100644
--- a/cake/libs/view/helpers/form.php
+++ b/cake/libs/view/helpers/form.php
@@ -678,7 +678,9 @@ class FormHelper extends AppHelper {
  * ### Options
  *
  * See each field type method for more information. Any options that are part of
- * $attributes or $options for the different **type** methods can be included in `$options` for input().
+ * $attributes or $options for the different **type** methods can be included in `$options` for input().i
+ * Additionally, any unknown keys that are not in the list below, or part of the selected type's options
+ * will be treated as a regular html attribute for the generated input.
  *
  * - `type` - Force the type of widget you want. e.g. `type => 'select'`
  * - `label` - Either a string label, or an array of options for the label. See FormHelper::label()