Errors:
Obsolete doctype. Expected “<!DOCTYPE html>”.
When the attribute “xml:lang” in no namespace is specified, the element must also have the attribute “lang” present with the same value.
Internal encoding declaration “iso-8859-1” disagrees with the actual encoding of the document (“utf-8”).
Bad value “text/html; charset=ISO-8859-1” for attribute “content” on element “meta”: “iso-8859-1” is not a preferred encoding name. The preferred label for this encoding is “windows-1252”.
Bad start tag in “iframe” in “head”.
Stray end tag “noscript”.
Stray end tag “head”.
Start tag “body” seen but an element of the same type was already open.
Bad value “periodictable” for attribute “rel” on element “a”: The string “periodictable” is not a registered keyword.
Bad value “newsletter” for attribute “rel” on element “a”: The string “newsletter” is not a registered keyword.
Duplicate ID “languagemenu”.
Bad value “en” for attribute “rel” on element “a”: The string “en” is not a registered keyword.
Malformed byte sequence: “e7”.
Malformed byte sequence: “f1”.
Bad value “fr” for attribute “rel” on element “a”: The string “fr” is not a registered keyword.
Bad value “de” for attribute “rel” on element “a”: The string “de” is not a registered keyword.
Bad value “es” for attribute “rel” on element “a”: The string “es” is not a registered keyword.
Bad value “it” for attribute “rel” on element “a”: The string “it” is not a registered keyword.
Malformed byte sequence: “93”.
Malformed byte sequence: “94”.
Bad value “intro01” for attribute “rel” on element “a”: The string “intro01” is not a registered keyword.
Bad value “intro02” for attribute “rel” on element “a”: The string “intro02” is not a registered keyword.
Bad value “intro03” for attribute “rel” on element “a”: The string “intro03” is not a registered keyword.
Malformed byte sequence: “96”.
Element “lang” not allowed as child of element “ul” in this context. (Suppressing further errors from this subtree.)
Warnings:
Consider avoiding viewport values that prevent users from resizing documents.
The “name” attribute is obsolete. Consider putting an “id” attribute on the nearest container instead.
The first occurrence of ID “languagemenu” was here.
This document appears to be written in English. Consider adding “lang="en"” (or variant) to the “html” start tag.
France FR