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The “version” attribute on the “html” element is obsolete.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The “profile” attribute on the “head” element is obsolete.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.
Attribute “http-equiv” not allowed on element “meta” at this point.
Element “meta” is missing one or more of the following attributes: “itemprop”, “property”.
Element “style” not allowed as child of element “noscript” in this context. (Suppressing further errors from this subtree.)
An “img” element must have an “alt” attribute, except under certain conditions. For details, consult guidance on providing text alternatives for images.
No “p” element in scope but a “p” end tag seen.
Bad value “” for attribute “name” on element “input”: Must not be empty.
Bad value “<?php print $base_path ?>first-rce-thematic-conference” for attribute “href” on element “a”: Illegal character in path segment: “<” is not allowed.
Duplicate ID “slider”.
Duplicate ID “slide-0”.
Duplicate ID “slide-1”.
Duplicate ID “slide-2”.
Duplicate ID “slide-3”.
Duplicate ID “slide-4”.
Duplicate ID “slide-5”.
Duplicate ID “slide-6”.
Duplicate ID “slide-7”.
Duplicate ID “htmlcaption-0”.
Duplicate ID “htmlcaption-1”.
Duplicate ID “htmlcaption-2”.
Duplicate ID “htmlcaption-3”.
Duplicate ID “htmlcaption-4”.
Duplicate ID “htmlcaption-5”.
Duplicate ID “htmlcaption-6”.
Duplicate ID “htmlcaption-7”.
Attribute “datatype” not allowed on element “span” at this point.
Attribute “content” not allowed on element “span” at this point.
End tag “section” seen, but there were open elements.
Unclosed element “div”.
End tag for “body” seen, but there were unclosed elements.
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 “banner” role is unnecessary for element “header”.
Empty heading.
The “navigation” role is unnecessary for element “nav”.
The first occurrence of ID “slider” was here.
The first occurrence of ID “slide-0” was here.
The first occurrence of ID “slide-1” was here.
The first occurrence of ID “slide-2” was here.
The first occurrence of ID “slide-3” was here.
The first occurrence of ID “slide-4” was here.
The first occurrence of ID “slide-5” was here.
The first occurrence of ID “slide-6” was here.
The first occurrence of ID “slide-7” was here.
The first occurrence of ID “htmlcaption-0” was here.
The first occurrence of ID “htmlcaption-1” was here.
The first occurrence of ID “htmlcaption-2” was here.
The first occurrence of ID “htmlcaption-3” was here.
The first occurrence of ID “htmlcaption-4” was here.
The first occurrence of ID “htmlcaption-5” was here.
The first occurrence of ID “htmlcaption-6” was here.
The first occurrence of ID “htmlcaption-7” was here.
This document appears to be written in English. Consider adding “lang="en"” (or variant) to the “html” start tag.
Consider using the “h1” element as a top-level heading only (all “h1” elements are treated as top-level headings by many screen readers and other tools).