Is it possible to indicate the requiredness of a `multipart/form-data`'s request's `filename` directive?

As far as I can tell, the required property in the OpenAPI spec can be used to specify that an entire multipart/form-data part is required, but it cannot be used to indicate whether the filename directive is required.

This would be pretty useful since some multipart/form-data endpoints require the filename directive while others do not. If OpenAPI allowed specifying those semantics, then that could be used in various generators that consume OpenAPI (e.g. an SDK generator could check whether the end-user supplied a filename if it's required).

Start by reading the OpenAPI multipart/form-data requirements and the linked Content-Disposition filename definition. Determine how required filename semantics could be represented for consumers such as SDK generators, and define completion through an agreed specification change with corresponding examples.