Errors:
Stray start tag “html”.
A document must not include both a “meta” element with an “http-equiv” attribute whose value is “content-type”, and a “meta” element with a “charset” attribute.
A “meta” element with an “http-equiv” attribute whose value is “X-UA-Compatible” must have a “content” attribute with the value “IE=edge”.
A document must not include more than one “meta” element with a “http-equiv” attribute whose value is “content-type”.
Bad value “tel: 020 8068 0798” for attribute “href” on element “a”: Illegal character in scheme data: space is not allowed.
Bad value “none” for attribute “role” on element “li”.
Attribute “aria-expanded” not allowed on element “button” at this point.
An element with “role=menuitem” must be contained in, or owned by, an element with “role=menubar” or “role=menu”.
Element “div” not allowed as child of element “ul” in this context. (Suppressing further errors from this subtree.)
Duplicate attribute “class”.
Bad value “” for attribute “id” on element “a”: An ID must not be the empty string.
Duplicate ID “cta-banner”.
Attribute “svg” not allowed on element “svg” at this point.
Attribute “mozallowfullscreen” not allowed on element “iframe” at this point.
Attribute “webkitallowfullscreen” not allowed on element “iframe” at this point.
Attribute “oallowfullscreen” not allowed on element “iframe” at this point.
Attribute “msallowfullscreen” not allowed on element “iframe” at this point.
The “allowtransparency” attribute on the “iframe” element is obsolete. Use CSS instead.
The “frameborder” attribute on the “iframe” element is obsolete. Use CSS instead.
The “scrolling” attribute on the “iframe” element is obsolete. Use CSS instead.
Bad value “ISO-8859-1” for attribute “charset” on element “script”: “iso-8859-1” is not a preferred encoding name. The preferred label for this encoding is “windows-1252”.
Start tag “a” seen but an element of the same type was already open.
Stray end tag “a”.
An “img” element must have an “alt” attribute, except under certain conditions. For details, consult guidance on providing text alternatives for images.
Warnings:
The “navigation” role is unnecessary for element “nav”.
“role="none"” is not yet supported in all browsers. Consider instead either using “role="presentation"” or “role="none presentation"”.
The “banner” role is unnecessary for element “header”.
Empty heading.
The first occurrence of ID “cta-banner” was here.
The “article” role is unnecessary for element “article”.
This document appears to be written in English. Consider adding “lang="en"” (or variant) to the “html” start tag.
United Kingdom GB