NGFB / WPSSO – What are “Meta Property Containers”?

The NextGEN Facebook (NGFB) and WPSSO plugins offer a “Meta Property Containers” option that you can enable / disable under their General Settings > Specific Websites and Publishers > Google / Schema tab. There are several ways to include Schema markup in webpages (see an Introduction to Structured Data from Google for examples):

  • JSON-LD machine-readable scripts for Google (see WPSSO JSON extension).
  • Microdata and RDFa markup of HTML tag attributes in theme templates (not recommended).
  • HTML meta tags in the webpage head section.

Microdata and RDFa markup is not recommended since theme templates manage layout, and are often unaware of specific content information like products, recipes, locations, videos, etc. JSON-LD and HTML meta tags on the other hand are added by plugins, which have a better understanding of their own data. ;-)

HTML meta tags are used for a number of markup standards, like Facebook’s Open Graph, Twitter Cards, and several standard SEO meta tags like the “canonical” and “description” meta tags:

HTML meta tags can even be used for Schema markup:

The downside of using HTML meta tags for Schema markup is they can only represent a single dimension — you cannot provide meta tags for other meta tags — unless you use a little trick I call “Meta Property Containers”. ;-) For example, here is a set of Schema meta tags for an image that includes information about its width and height:

So why use “Meta Property Containers”? Its’ the second best option to using JSON-LD markup. ;-)