line 9 column 1 - Info: value for attribute "cellspacing" missing quote marks
line 9 column 1 - Info: value for attribute "border" missing quote marks
line 9 column 1 - Info: value for attribute "cellpadding" missing quote marks
line 9 column 1 - Info: value for attribute "width" missing quote marks
line 13 column 1 - Warning: <center> isn't allowed in <tr> elements
line 10 column 9 - Info: <tr> previously mentioned
line 13 column 1 - Warning: missing </center> before <td>
line 13 column 1 - Warning: trimming empty <center>
Info: Doctype given is "-//W3C//DTD HTML 4.0 Transitional//EN"
Info: Document content looks like HTML 4.01 Transitional
Info: No system identifier in emitted doctype
Tidy found 3 warnings and 0 errors!

One or more empty elements were present in the source document but
dropped on output. If these elements are necessary or you don't want
this behavior, then consider setting the option "drop-empty-elements"
to no.

About HTML Tidy: https://github.com/htacg/tidy-html5
Bug reports and comments: https://github.com/htacg/tidy-html5/issues
Official mailing list: https://lists.w3.org/Archives/Public/public-htacg/
Latest HTML specification: https://html.spec.whatwg.org/multipage/
Validate your HTML documents: https://validator.w3.org/nu/
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Do you speak a language other than English, or a different variant of 
English? Consider helping us to localize HTML Tidy. For details please see 
https://github.com/htacg/tidy-html5/blob/master/README/LOCALIZE.md