line 1 column 1 - Warning: missing <!DOCTYPE> declaration
line 7 column 5 - Warning: missing </i> before </dd>
line 7 column 16 - Warning: discarding unexpected </i>
Info: Document content looks like HTML5
3 warnings, 0 errors were found!

About HTML Tidy: https://github.com/htacg/tidy-html5
Bug reports and comments: https://github.com/htacg/tidy-html5/issues
Or send questions and comments to: https://lists.w3.org/Archives/Public/public-htacg/
Latest HTML specification: http://dev.w3.org/html5/spec-author-view/
Validate your HTML documents: http://validator.w3.org/nu/
Lobby your company to join the W3C: http://www.w3.org/Consortium