There are services that on presentation of identifying personal information (PI) provide further personal information. These include government data sources, credit reference agencies and fraud prevention services.
In the case when these services hold PI about the data subject and produce a response based on that I assume this would be personal information, and GDPR Article 14 would apply to the receiving data controller.
In the case when these services do not hold PI about the data subject, and produce a response based on that, perhaps something like "No Data" or NULL, is that itself personal information such that Art. 14 applies?
Take for example Cifas which holds multiple databases, approximately victims and perpetrators of fraud. They allow financial organisations to submit PI and receive information if the data subject has perpetrated a fraud or applied for protective registration. In the case an individual is in their databases and details are shared, this seems clearly a data transfer under the GDPR, and Art. 14 would apply. The majority of such requests are likely to come back negative, as most people are neither fraudsters nor registered victims. In this case the financial organisation knows something it did not before, but it is only "negative information". Is the fact that in individual is not on any Cifas database Personal Information?