RDFa

 RDFa  is a way of embedding RDF in HTML that has maybe one or a few publishers on the indieweb, but no known consuming use-cases, perhaps due to being unnecessarily more verbose than Microformats as demonstrated by the example documented at kevinmarks.com/microformatschema.html.

RDFa adds several attributes to standard HTML:  to specify an RDF resource type,   to specify the schema containing the type, and (much more plentifully)   to specify the field names described by markup nodes. Microformats use the already existing  attribute for all these purposes, following common Semantic HTML practices.

Minimal markup example
This is a minimal article, with microformats, microformats2, and RDFa, in HTML5.   article title 

Short summary of the article.

Long article body

1970-01-01 00:00, by                 Author Name  , published by                    domain.com https://domain.com