Highlight deprecation notice

content/docs/refs-and-the-dom.md

@@ -328,7 +328,11 @@ In the example above, `Parent` passes its ref callback as an `inputRef` prop to
 
 ### Legacy API: String Refs
 
-If you worked with React before, you might be familiar with an older API where the `ref` attribute is a string, like `"textInput"`, and the DOM node is accessed as `this.refs.textInput`. We advise against it because string refs have [some issues](https://github.com/facebook/react/pull/8333#issuecomment-271648615), are considered legacy, and **are likely to be removed in one of the future releases**. If you're currently using `this.refs.textInput` to access refs, we recommend the callback pattern instead.
+If you worked with React before, you might be familiar with an older API where the `ref` attribute is a string, like `"textInput"`, and the DOM node is accessed as `this.refs.textInput`. We advise against it because string refs have [some issues](https://github.com/facebook/react/pull/8333#issuecomment-271648615), are considered legacy, and **are likely to be removed in one of the future releases**. 
+
+> Note
+>
+> If you're currently using `this.refs.textInput` to access refs, we recommend the callback pattern instead.
 
 ### Caveats with callback refs