DOC Note that DBField formatters on array getters render empty in CMS 6

en/08_Changelogs/6.0.0.md

@@ -994,6 +994,7 @@ As part of the [improved separation between the view and model layers](#view-lay
 - Native indexed PHP arrays can now be passed into templates and iterated over with `<% loop $MyArray %>`.
   - Under the hood they are wrapped in [`ArrayList`](api:SilverStripe\Model\List\ArrayList), so you can get the count using `$MyArray.Count` and use `<% if $MyArray %>` as a shortcut for `<% if $MyArray.Count %>`.
   - Other functionality from `ArrayList` such as filtering and sorting cannot be used on these arrays since they don't have keys to filter or sort against.
+  - Because arrays are no longer cast to a `DBField`, calling a `DBField` formatter on a getter that returns an array without a `$casting` entry now renders an empty string. For example, `$MyGetter.JSON` rendered JSON in CMS 5 but renders nothing in CMS 6. Return the encoded string from a separate getter instead (e.g. `$MyGetterJSON`), or declare a `$casting` type for the getter. Note that a getter with a `$casting` type can no longer be looped over.
 - Arguments are now passed into getter methods when invoked in templates. For example, if a model has a `getMyField(...$args)` method and `$MyField(1,2,3)` is used in a template, the args `1, 2, 3` will be passed in to the `getMyField()` method.
 - Values from template variables are passed into functions when used as arguments
   - For example, `$doSomething($Title)` will pass the value of the `Title` property into the `doSomething()` method. Previously `"$Title"` would be passed as a string. See [template syntax](/developer_guides/templates/syntax/#variables) documentation for more details.