The <html> element should provide the lang and/or xml:lang attribute in order to identify the
default language of a document.
It enables assistive technologies, such as screen readers, to provide a comfortable reading experience by adapting the pronunciation and accent to the language. It also helps braille translation software, telling it to switch the control codes for accented characters for instance.
Other benefits of marking the language include:
Both the lang and the xml:lang attributes can take only one value.
<!DOCTYPE html> <html> <!-- Noncompliant --> <head> <title>A page written in english</title> <meta content="text/html; charset=utf-8" /> </head> <body> ... </body> </html>
<!DOCTYPE html> <html lang="en"> <head> <title>A page written in english</title> <meta content="text/html; charset=utf-8" /> </head> <body> ... </body> </html>
<!DOCTYPE html> <html lang="en" xml:lang="en"> <head> <title>A page written in english</title> <meta content="text/html; charset=utf-8" /> </head> <body> ... </body> </html>