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.

'\n    in table (at **)' +
              '\n    in Table (at **)' +
              '\n    in FancyTable (at **)'
          : 'See FancyTable > Table > table > FancyRow > Row > tr.',
      );
      ReactTestUtils.renderIntoDocument(<table><FancyRow /></table>);
      expectDev(console.error.calls.count()).toBe(4);
      expectDev(
        normalizeCodeLocInfo(console.error.calls.argsFor(3)[0]),
      ).toContain(
        ReactDOMFeatureFlags.useFiber
          ? '\n    in tr (at **)' +
              '\n    in Row (at **)' +
              '\n    in FancyRow (at **)' +
              '\n    in table (at **)'
          : 'See table > FancyRow > Row > tr.',
      );
      ReactTestUtils.renderIntoDocument(<FancyTable><tr /></FancyTable>);
      expectDev(console.error.calls.count()).toBe(5);
      expectDev(
        normalizeCodeLocInfo(console.error.calls.argsFor(4)[0]),
      ).toContain(
        ReactDOMFeatureFlags.useFiber
          ? '\n    in tr (at **)' +
              '\n    in table (at **)' +
              '\n    in Table (at **)' +
              '\n    in FancyTable (at **)'
          : 'See FancyTable > Table > table > tr.',
      );
      class Link extends React.Component {