Yandex Market Language YML. Can additional fields be added?

Question

Yandex Market Language

To import goods to ourselves, we want to use the yml format, which partner sites usually already have and use. But we need to add a couple of our fields.
Does Yandex swear at unfamiliar fields?

Answer 1

And what prevents you from creating two separate YML for Yandex and for integration with you?