When searching for records of eg a genus: https://records.nbnatlas.org/occurrence … ecordsView, the drop down box next to the results count includes a multi select of the child taxa included in the search, but also includes a "not supplied" value (see attached). Ticking this and refining the search gives me:

No records found for Scientific name (unprocessed):"Not supplied"

The count of "not supplied" records appears to be included in the total results count which suggests there are some records to be found. Going via the filters on the left hand side and filtering the Scientific name (unprocessed) to "not supplied" results in 820 returned records (which have a taxon key, but no scientific name supplied, hence the "not supplied" I guess)