Which meta names are case-sensitive?

Question

I am the developer of an HTML checking tool. I want to check meta names to make sure they match case-sensitively when it matters. All I've come across so far (according to Google) is that this meta name ("google-site-verification") should be case sensitive as in:

<meta name="google-site-verification" content="XXX">

That is, you would not want to use this:

<meta name="GOOGLE-SITE-verification" content="XXX">

Are there any other meta names that are case-sensitive? I'd like to check for this in my tool.

UPDATE: Looks like Microsoft has many more that are case-sensitive, most of which are msapplication-*: http://msdn.microsoft.com/en-us/library/ie/dn255024.aspx

Answer 1

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Google is a little bit over exact on this to avoid requests on the verification topic. It's the content="" part of the verification meta-tag which has to be case sensitive. Not the name="" part as you post it in your answer. Google verifies with help of this meta tag even if the name-part is NOT written as they provide it. So

<meta name="goOgle-sIte-verIficatiOn" content="CaseSensitiveStringASGoogleProvidetIt">

will work fine as does

<meta name="GOOGLE-SITE-VERIFICATION" content="CaseSensitiveStringASGoogleProvidetIt">. (I have tested that.)

This is also consistent with their webmaster help: https://support.google.com/webmasters/answer/79812?hl=en

With the exception of verify, case is generally not important in meta tags. (This is also the official answer to your question, the case in meta-tag-names is generally irrelevant. As it is according to my own experience.)

If your HTML-checking tool should work like Google did, you could generate a warning, but the website should pass your check, even with this "problem" because it still works fine.

As to the "verify-v1" name, I'm not sure if this is still a valid method? On the recent official tools and help pages Google only talks about the google-site-verification tag...

Answer 2

In HTML5, there are two sets of metadata names:

• standard metadata names, defined in the HTML5 spec
• other metadata names, registered on the WHATWG wiki page MetaExtensions

For the standard metadata names, it is required that they are case-insensitive:

Names are case-insensitive, and must be compared in an ASCII case-insensitive manner.

For other metadata names, it says:

The name should not be confusingly similar to any other defined name (e.g. differing only in case).

Note the "should". So registered values may be case-sensitive.