Subheaders/headers are not handled. Admin provided this page (https://instantview.telegram.org/contest/neva.today/template12/?url=https%3A%2F%2Fneva.today%2Fnews%2Fafisha-v-peterburge-14-15-marta-kino-teatry-vystavki-koncerty-108480%2F) as proof of stateьуте, that highlighted parts are not subheaders. But these parts was used with the same purpose (to specify an event) as subheaders on provided page. So it should be equally marked up