In order to improve the policy of multilingual support of this web site, I have added a few lines in the CSS file of the default theme. These lines:

a[hreflang]:after {
     font-weight: bold;
     font-size: 75%;
     content: " [" attr(hreflang) "]";
}

make that links where hreflang atribute has been specified, show next to them the language of the contents of the referring URL. Ex:
<a href='http://www.w3.org/International/tests/sec-hreflang-style-1' hreflang='en' >

For learning more about web creation and design, you can take a look at a few webs in Catalan I recommend in this piece of news at Softcatalà. You may also prefer to know more by searching this related Dmoz directory.

I first knew this functionality in Mozilla Europe, Pascal and Tristan webpages.