julienvdg

hreflang Flag plugin uses <a href="http://www.w3.org/TR/css3-selectors/#attribute-selectors" title="W3C CSS3 Attribute selectors description" rel="nofollow ugc">css3 selectors</a> to add a flag icon to your links depending on their <a href="http://www.w3.org/TR/html401/struct/links.html#adef-hreflang" title="hreflang attribute description on W3C" rel="nofollow ugc">hreflang attribute</a>.
This is really useful if you regularly link to pages in other languages and you want to inform your visitors about the language of the link target.
It’s even more useful if your own blog is multilingual.

hreflang Flag

Add a flag icon to link corresponding to the hreflang attribute.

Alex Zappa

The lang attribute specifies the language of the element’s content. 
Common examples are “en” for English, “es” for Spanish, “fr” for French, and so on. 
This plugin slice the language attribute for HTML tag, For example: lang=”en-US” to lang=”en”

HTML Global lang Attribute

This plugin slice the language attribute for HTML tag, For example: lang="en-US" to lang="en"

hreflang Flag vs HTML Global lang Attribute