This YAML file can be extended by authors to include additional metadata.
F3: Metadata clearly and explicitly include the identifier of the data they describe
Yes. In the example above, the metadata file contains a clear link to the data it describes.
F4: (Meta)data are registered or indexed in a searchable resource
Partly. For scholarly content, all metadata and identifiers are indexed and crawled daily by Google and other search engines. All Authorea content is visible and presented in Google Scholar as well. However, data folders are not systematically crawled and indexed.