Jean-Fran├žois Rabasse | 25 Nov 10:52 2014

Re: RSS feed validator


Cf. message from Gerard Kanters, Thu, 6 Feb 2014 11:08:30

> With the W3C feed validator has an issuei
> with the <enclosure> tag
> If that contains a file which is https:// instead of http:// it will
> fail and provides this error:
> url must be a full URL:
> If I rewrite the URL to http:// it will pass.
> I would either recommend the RSS standard to support https or fix the
> validator.  I'd like your opinion on this.

I have a - more or less - similar issue when validating <enclosure> items.

My RSS feed has been validating correctly for years, and validation recently
broke after I changed my site domain name :-(

Former name was, and the URLs ""
passed the validation.

The new name is (I've registered one of the new ICANN-era
generic TLD), and the new URLs "" are no
longer recognized; the validator writes the same message as for Gerard :
url must be a full URL

(Continue reading)

Carl Smith | 24 Nov 12:55 2014

[VE][81] character X not allowed in attribute specification list

Error [81]: "character X not allowed in attribute specification list"

The vast majority of the errors were created due to a script in the head, however the validator was unable to detect this, and so processed the script like as if it was HTML.

Anton Andrushchenko | 24 Nov 12:34 2014

Add Subject Here


we are getting very strange error message trying to validate our website: 

The message says: 

Sorry, I am unable to validate this document because its content type is text/html,, which is not currently supported by this service.
The Content-Type header is sent by your web server (or web browser if you use the file upload interface) and depends on its configuration. Commonly, web servers will have a mapping of filename extensions (such as ".html") to MIME Content-Type values (such as text/html).

Looks like the content-type property value is treated as comma-trailed, but we don’t have this neither in the HTML code not in response headers of the server. 

Kindly asking you to explain why this happens to our website, currently we have checked everything and did not find the cause.. 

Best Regards, 
Anton Andrushchenko
CTO at Westsidewholesale, Inc

Tushar Goyal | 20 Nov 16:26 2014


I have a simple question:

I have a website, and uses BBcode. When I enable BBcode
usage the w3 validator gives 19 errors. Without it, no errors:


Anyone can explain me what to do?

Thank you!

Jason McNeil

Web designer

Web World SRL

EXT: 4298




Richard | 19 Nov 23:29 2014

My first HTML5 page - 1 warning - no details

Having spent many years hand coding HTML 4.1 I decided to see if I could
convert to HTML5

After editing out all the errors initially reported by your Validator
service, I was left with just 1 warning - but no details

I have double checked as best I can (being new to HTML5) 

Please advise if possible?

Here is my "new" file

Many thanks!

Richard Nourse
Tel: 01929 554690 (home)  - Mob: 07814 784748
Your PC can fight AIDS & cancer
Free SPAM killer: 
Free VIRUS killer: 
Junk Phone Calls?

Branscome, April | 18 Nov 21:08 2014

Validation Service Blocked - Please Whitelist Schools


My name is April Branscome, and I am CHOICE IT Specialist for the Okaloosa County School District.  We have a Web design program in all of our middle and high schools, and each of our programs use the W3C Validation service. 

Today one of our teacher was reviewing how to validate HTML/CSS code with her Web 3 students, and they were unable to do so through the W3C.  Apparently, the W3C Web site blocked their IP because there were too many people visiting the Web site at one time.  

Can you whitelist the IPs for the school district? The IP for the school that was using the validator according to is

The W3C Validation Service is a wonderful tool for our students to use to check their work.

Thank you for your consideration.


April Branscome
CHOICE IT Specialist

branscomea <at>

(850) 833-5858


CHOICE, not chance, determines destiny!


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Darwin Junior | 13 Nov 21:19 2014

[VE][html5] Add Subject Here

hi, please send me a solution for the errors founded in my website!


Darwin Jr

Error [html5]: ""
Jamie Gill | 13 Nov 18:25 2014

Validation Error for SVG

Hi there,

I hope your well I have received the following error on your validation system :-

Attribute src not allowed on element image at this point.

For this line of code :-

<svg width="300px" height="50px">
      <image xlink:href="/images/sterling_logo.svg" src="/images/sterling-gosling_logo.png" width="300px" height="50px"  />

I understand the validation on the basis of xlink and src been in the same tag. However this is an extremely good fallback for earlier version of IE instead of having an SVG and then IMG tags in conditional statements creating unnecessary lines of code for a fallback.

Is there any reason why this would be or why it is not allowed to validate this way? Obviously I take pride in my code validating and wondered if this is something that maybe passed to validate in the future? The URL for my document is :-

Thank you for your time I look forward to your reply,


PS Website Design Ltd

Office: + 44 (0) 1943 605 894

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Alice Wonder | 10 Nov 23:45 2014

typesmustmatch xhtml

When the object tag has the typesemustmatch attribute, the W3C validator 
states that it is not allowed in xhtml at this point.

Everything else will validate as html5

Why is that attribute listed in the html5 specification w/o a special 
note if it is not allowed when sending the content as 
application/xml+xhtml ?? How am I suppose to know what really is allowed 
when serving as XML if the spec does not tell me?

That says nothing about the tag not being allowed when an html5 document 
is sent as xml.

This is why that attribute is important to me, and why I would like it 
to be part of html5 even when sent as XML :

When the webapp I am writing scans content before serving, object nodes 
that are not in a whitelist of type attributes are removed, to help 
prevent XSS.

Object nodes within the whitelist, I want to add that attribute because 
if the browser is not implementing CSP then I don't want an 
intentionally mis-identified type attribute in an injection attack to 
allow a payload to be delivered to users.

I'm hoping typesmustmatch will help prevent that scenario.

I have to allow the object tag, it is useful for several things, but it 
is also dangerous.

Historically some browsers *cough*IE*cough* would sometimes think they 
were being helpful in scenarios where mime type didn't match what IE 
thought it was, resulting in attack vectors. I want to be able to 
specify that they MUST match for pages served from my app.

So I really want that attribute to be legal in html5 - even when I send 
as XML which is what I prefer to do.

Thank you,


Benjamin Lehmann | 7 Nov 16:51 2014

The validation service doesn't support PHP

You cannot check PHP files with your validation service.

I would either recommend adding full PHP support, or treating PHP files as HTML, and ignore the <?php ?> tags.

Thank you in advance.
Mark Rogers | 8 Nov 20:59 2014

Unicode Character 'PILE OF POO' (U+1F4A9) and validator test suite



Is the Unicode character U+1F4A9 used in the conformance checker test suite for URLs really invalid? It’s marked as novalid in test suite files like:




In RFC 3987 this character is listed in the 10000-1FFFD  range in the iuserinfo  -> iunreserved -> ucschar production:


iuserinfo      = *( iunreserved / pct-encoded / sub-delims / ":" )


iunreserved    = ALPHA / DIGIT / "-" / "." / "_" / "~" / ucschar


   ucschar        = %xA0-D7FF / %xF900-FDCF / %xFDF0-FFEF

                  / %x10000-1FFFD / %x20000-2FFFD / %x30000-3FFFD

                  / %x40000-4FFFD / %x50000-5FFFD / %x60000-6FFFD

                  / %x70000-7FFFD / %x80000-8FFFD / %x90000-9FFFD

                  / %xA0000-AFFFD / %xB0000-BFFFD / %xC0000-CFFFD

                  / %xD0000-DFFFD / %xE1000-EFFFD


In the Whatwg URL standard it’s listed as a valid URL code point, and will be converted to percent encoding during the normalisation process, but won’t flag an error. See


Best Regards



Mark Rogers - <at>
PowerMapper Software Ltd -

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