[whatwg] How to make HTML5 easier to teach (Was: several messages about HTML5)

Henri Sivonen hsivonen at iki.fi
Sat Feb 24 06:09:56 PST 2007

On Feb 24, 2007, at 13:24, Keryx Web wrote:

> I would also like to see that the conformance checking software  
> would give me a graded output:
> 1. Warning - technically allowed but bad practice
> 2. Error - not according to the spec
> 3. Fatal error - most browsers will not be able to parse at all

The semantics for the warnings, errors and fatal errors emitted by  
http://hsivonen.iki.fi/validator/html5/ are as follows:

Warning: Something that I think is harmful but there's no spec that  
would allow me to call it an error or something that technically  
conforming bet is extremely likely a mistake made by the author. OR:  
Something that a spec makes an error in most cases, but determining  
if it indeed is a spec violation requires inspection by a human.

Error: Violation of a conformance requirement in any supported spec  
and the violation does not cause the checker to stop.

Fatal error: Violation of a conformance requirement upon which  
checking stops. These include errors that the XML spec requires to be  
treated as fatal and HTML parse errors that I have chosen not to try  
to recover from. OR: The input triggers a defense mechanism against  
denial of service attacks without actually violating any spec.

Henri Sivonen
hsivonen at iki.fi

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