Dublin Core metadata

[jasonkarns]

A more comprehensive grammar of attributes for richer metadata information.

http://dublincore.org/documents/dcq-html/

[selfthinker]

A lot of the Dublin Core metadata is invalid in HTML5.
So, if/when it gets added, there should at least be a little warning.

[bmix]

Are those DC metadata items also invalid in XHTML5?

[jasonkarns]

Most of what is said in that stackoverflow accepted answer isn't entirely correct (other followup answers explain). The SO post states that additional link relations need to be added to the registry. Except the spec itself only states may. And for the table of listed meta values, the spec itself states the table is non-normative.

Also, the DC metadata is listed in the valid meta extensions table from whatwg. (https://wiki.whatwg.org/wiki/MetaExtensions) which is a wiki so adding other meta extensions is essentially open-ended.

In short, dublin core metadata is valid in both HTML5 and XHTML.

[selfthinker]

I think it was correct at the time, but things have changed since then. The HTML validator has also been updated since then. All (or most?) Dublin Core metadata is valid HTML5 nowadays.

[joshbuchea]

Would be curious to hear a few more opinions on this matter. I haven't researched it enough yet to determine what I think should be included in this project.

@jasonkarns any chance you'd want to open a PR? Apologies if we/I already asked you in the past, I only ask because you've been the biggest advocate for Dublin Core metadata in this project.