I agree with what others say that the subject is very vague. Never the less I will attempt to express my thoughts on the matter and show you how I’m doing it on my blog. I use both WebPage and Blog item types in the same document to mark up different things. Web page I … Read more
*Edit, May 2015: Times have changed… again. Schema.org seems the way to go, using either microdata (W3C note) or RDFa (W3C recommendation), where the RDFa Lite variant is easiest to learn. Meanwhile recently Microformats released a new version as well, which nobody is paying attention to currently. Also see the answer to What is the … Read more
If a meta element has an itemprop attribute and a content attribute, and has no name attribute, no http-equiv attribute, and no charset attribute, then it’s valid to have this meta in the body. (If the value is a URL, you must use link instead.) Why? Because the Microdata specification changes HTML5. (Note that RDFa … Read more
Consumers that support Microdata support Microdata, no matter if or where Microdata is specified. It’s conceivable that new consumers might decide not to support it, but the syntax is still very popular and still part of WHATWG’s HTML Living Standard, so it’s probably not going to vanish. About the consumer Google Some years ago, JSON-LD … Read more
Schema.org is a vocabulary that can, like any other vocabulary, be used in many forms. The website http://schema.org/ has examples using Microdata and the RDF syntaxes RDFa and JSON-LD, but these are not the only syntaxes it can be used with. You could, for example, use it with any other RDF syntax like Turtle or … Read more
Differences between Microdata and RDFa While there are many (technical, smaller) differences, here’s a selection of those I consider important (used my answer on Webmasters as a base). Specifications As W3C’s HTML WG found no volunteer to edit the Microdata specification, it is now merely a W3C Group Note (see history), which means that there … Read more
So, to start with a couple of cliche’s and mangled metaphors – we’re talking apples and oranges a bit comparing OG and Schema.org, and when it comes to this metadata it’s horses for courses. The right answer depends on your intent, in adding metadata to your page. What is it that you’re hoping to gain? … Read more