Cannot get OpenGraph (Facebook) tags to validate
When I use this header:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML+RDFa 1.0//EN" "http://www.w3.org/MarkUp/DTD/xhtml-rdfa-1.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:og="http://ogp.me/ns#" xml:lang="nl-NL">
Then I can delcare Facebook meta tags for my page like:
<meta property="og:type" content="book" />
This validates well in W3C's (http://validator.w3.org) online validator and checkrdfa (http://check.rdfa.info/), but CSE requires the Meta tag to be prefixed:
<og:meta property="og:type" content="book" />
However this fails on W3C's validator (element "og:meta" undefined)!
All online examples I've come across do not prefix the Meta tag.
Otherwise, Facebook testpage (http://developers.facebook.com/tools/lint) does not recognize any meta tags, prefixed nor un-prefixed, maybe something else is wrong?
It gives a warning about missing meta tags which are listed in the debug view...
See my testpage:
http://www.vrijezending.nl/FaceBookTest.html
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML+RDFa 1.0//EN" "http://www.w3.org/MarkUp/DTD/xhtml-rdfa-1.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:og="http://ogp.me/ns#" xml:lang="nl-NL">
Then I can delcare Facebook meta tags for my page like:
<meta property="og:type" content="book" />
This validates well in W3C's (http://validator.w3.org) online validator and checkrdfa (http://check.rdfa.info/), but CSE requires the Meta tag to be prefixed:
<og:meta property="og:type" content="book" />
However this fails on W3C's validator (element "og:meta" undefined)!
All online examples I've come across do not prefix the Meta tag.
Otherwise, Facebook testpage (http://developers.facebook.com/tools/lint) does not recognize any meta tags, prefixed nor un-prefixed, maybe something else is wrong?
It gives a warning about missing meta tags which are listed in the debug view...
See my testpage:
http://www.vrijezending.nl/FaceBookTest.html