For one thing, only a part schema is described here, but anyway it's too big and subject to change to be appropriate to copy and paste into here. Possibly a $ref supporting oneOf the list of available pdtf schema versions should be included, but should probably leave it as a JSON object that self-describes its schema (in its own required $schema field).
https://github.com/Property-Data-Trust-Framework/api/blob/196423fdfd02b2ad7aa256da251740062cdfae2c/pdtf-baseline-api-1.0.1.yml#L439-L530
For one thing, only a part schema is described here, but anyway it's too big and subject to change to be appropriate to copy and paste into here. Possibly a $ref supporting oneOf the list of available pdtf schema versions should be included, but should probably leave it as a JSON object that self-describes its schema (in its own required $schema field).