Thanks. I researched it of q2a V1.8.
Certainly microdata is one way of schema.org, but this way has some problems. If I develop it, I will use JSON-LD. Anyway, the concept of schema.org is still does not seem to penetrate the public. Therefore, I think that feature is premature.
A example of microdata problem:
http://www.question2answer.org/qa/49479/
