Meta tags for different languages

问题:

I'm making a multi-language website and I'm sure that I saw a while ago that there is a meta tag to tell search engines the URL of the same page in a different language.

I'm currently using the language tag below, but is there another tag to list the same pages URL in different languages?

<meta http-equiv="content-language" content="en">

Something like??

<meta http-equiv="alternative-language" content="es" ref="/es/page.php">

回答1:

Never used it, but in theory:

<link rel="alternate" href="/es/page.php" hreflang="es" type="text/html">