This usually means that the user mixed up our lowercase/uppercase naming convention; see https://github.com/facebook/react/pull/3429#issuecomment-85166440.

We could add a message like

> Warning: The tag <commentBox> is unrecognized in this browser. If you meant to render a React component, start its name with an uppercase letter.

We'd check this only once per tag and only in development mode.

);
        didWarnShadyDOM = true;
      }
    }
    var props: Object;
    switch (tag) {
      case 'audio':
      case 'form':
      case 'iframe':
      case 'img':
      case 'image':
      case 'link':
      case 'object':
      case 'source':
      case 'video':
      case 'details':
        trapBubbledEventsLocal(domElement, tag);
        props = rawProps;
        break;
      case 'input':
        ReactDOMFiberInput.mountWrapper(domElement, rawProps);
        props = ReactDOMFiberInput.getHostProps(domElement, rawProps);
        trapBubbledEventsLocal(domElement, tag);
        
        
        ensureListeningTo(rootContainerElement, 'onChange');
        break;
      case 'option':
        ReactDOMFiberOption.mountWrapper(domElement, rawProps);
        props = ReactDOMFiberOption.getHostProps(domElement, rawProps);