Zotero’s browser plugin has a number of site-specific translators, but also some generic ones, that support some metadata, like OpenGraph.

The entry point is the “Embedded Metadata” translator. Unfortunately, it doesn’t support any modern forms of metadata, neither JSON-LD nor microdata. It supports <meta> tags, however, and treats them as RDF. There’s no good documentation on this, and reading the RDF translator’s code is required to find out which subsets of which schemas it supports.

For our blog posts, we’ve settled on the following attributes:

<!-- We can't use https and the trailing slash is required, otherwise Zotero won't detect the metadata -->
<link rel = "schema.so" href    = "http://schema.org/">
<link rel = "schema.og" href    = "http://ogp.me/ns#">
<meta name = "rdf:type" content = "http://schema.org/BlogPosting">
<meta name = "so:headline" content = "...">
<meta name = "so:author" content = "LastName, FirstName">
<!-- Zotero's RDF translator only supports so:datePublished, not so:dateCreated -->
<meta name = "so:datePublished" content = "2006-01-02">
<meta name = "so:inLanguage" content = "en">
<meta name = "og:site_name" content = "...">