The short answer, is yes. But, they prefer and advise Microformat.
Developing websites for Yandex is not as daunting a task as it might appear at first, and everything starts with understanding structured data mark-up and JSON Schema.
JSON Schema is a way of describing the structure of structurally sound JSON documents in terms of their data types, field names, allowed values for each field, etc. so that both humans and machines can read them more readily. Yandex and Google both support JSON schema and it is a good idea to start marking up your website with it if you haven’t already done so.
JSON schema support in Yandex & Google
JSON-S is a JSON-based format for defining the specific field and data type requirements of JSON objects (in essence, a schema).
Yandex supports the standard version 1.0 of the format, as do some search engines like DuckDuckGo.
In March 2015 Google announced that its crawler would consider content marked up in the standard version 2.0 of JSON-S as rich results in search results pages for queries that match the data types contained within them. The standard version 2.0 is currently supported by Yandex as well, but it has not been formally announced. Bing supports the standard version 1.0 of JSON schema as well.
Google’s open-source project, Schema-org, supports both versions 1.0 and 2.0 of JSON-S.
You can read Yandex’s documentation on Schema implementations here.
