Errors:
Legacy doctype. Expected “<!DOCTYPE html>”.
Attribute “xmlns:content” not allowed here.
Attribute “xmlns:dc” not allowed here.
Attribute “xmlns:foaf” not allowed here.
Attribute “xmlns:og” not allowed here.
Attribute “xmlns:rdfs” not allowed here.
Attribute “xmlns:sioc” not allowed here.
Attribute “xmlns:sioct” not allowed here.
Attribute “xmlns:skos” not allowed here.
Attribute “xmlns:xsd” not allowed here.
When the attribute “xml:lang” in no namespace is specified, the element must also have the attribute “lang” present with the same value.
The “version” attribute on the “html” element is obsolete. You can safely omit it.
The “profile” attribute on the “head” element is obsolete. To declare which “meta” terms are used in the document, instead register the names as meta extensions. To trigger specific UA behaviors, use a “link” element instead.
An “img” element must have an “alt” attribute, except under certain conditions. For details, consult guidance on providing text alternatives for images.
Duplicate ID “main”.
Attribute “about” not allowed on element “div” at this point.
Attribute “content” not allowed on element “span” at this point.
Attribute “datatype” not allowed on element “span” at this point.
Stray end tag “div”.
The “aria-labelledby” attribute must point to an element in the same document.
Warnings:
Attribute with the local name “xmlns:content” is not serializable as XML 1.0.
Attribute with the local name “xmlns:dc” is not serializable as XML 1.0.
Attribute with the local name “xmlns:foaf” is not serializable as XML 1.0.
Attribute with the local name “xmlns:og” is not serializable as XML 1.0.
Attribute with the local name “xmlns:rdfs” is not serializable as XML 1.0.
Attribute with the local name “xmlns:sioc” is not serializable as XML 1.0.
Attribute with the local name “xmlns:sioct” is not serializable as XML 1.0.
Attribute with the local name “xmlns:skos” is not serializable as XML 1.0.
Attribute with the local name “xmlns:xsd” is not serializable as XML 1.0.
The first occurrence of ID “main” was here.
This document appears to be written in Italian. Consider adding “lang="it"” (or variant) to the “html” start tag.
Italy IT