Errors:
A “meta” element with an “http-equiv” attribute whose value is “X-UA-Compatible” must have a “content” attribute with the value “IE=edge”.
Bad value “https://plus.google.com/{+PageId}” for attribute “href” on element “link”: Illegal character in path segment: “{” is not allowed.
The “scrolling” attribute on the “iframe” element is obsolete. Use CSS instead.
The “frameborder” attribute on the “iframe” element is obsolete. Use CSS instead.
The “allowtransparency” attribute on the “iframe” element is obsolete. Use CSS instead.
Stray start tag “head”.
Stray end tag “head”.
An “img” element must have an “alt” attribute, except under certain conditions. For details, consult guidance on providing text alternatives for images.
Quote “"” in attribute name. Probable cause: Matching quote missing somewhere earlier.
Duplicate attribute “frameborder”.
Attribute “allowfullscreen"” not allowed on element “iframe” at this point.
The “align” attribute on the “div” element is obsolete. Use CSS instead.
No “p” element in scope but a “p” end tag seen.
Duplicate ID “col1”.
Duplicate ID “content”.
End tag “br”.
Warnings:
Consider avoiding viewport values that prevent users from resizing documents.
Attribute “allowfullscreen"” is not serializable as XML 1.0.
The first occurrence of ID “col1” was here.
The first occurrence of ID “content” was here.
The “main” role is unnecessary for element “main”.
This document appears to be written in English but the “html” start tag has “lang="pl"”. Consider using “lang="en"” (or variant) instead.
Poland PL