こんにちは。
永原です。

多言語サイトの作成でrel=”alternate” hreflang=”xx” について、必要性や方法を調査してみます。

出力例①
<link rel="alternate" href="http://www.example.com/ja" hreflang="ja" />
<link rel="alternate" href="http://www.example.com/en" hreflang="en" />

出力例②
<link rel="alternate" href="http://www.example.com/" hreflang="ja" />
<link rel="alternate" href="http://www.example.com/en" hreflang="en" />