Can you explain in more detail to how the GDPR applies to unstructured forms? Would those be forms specifically for inputing personal data, or any free text at all?
Any personal data is subject, whether it is contained in Word documents, PowerPoints (that could be image based scans that will need to be OCRd to make them discoverable), spreadsheets, text files, database dumps, PST files, CSV files, etc, etc.
If it contains personal data on an EU natural person regardless of where the company is based is based, or on any natural person anywhere if the company is EU based, it is subject to the GDPR.
My question is more, what if you don't know it has personal data? Say you're just a generic document storage & sharing service, and someone uploads a generic PDF or Word, but which happens to contain personal data. Surely you're not expect to treat any possible data you receive as personal, just in case?
If it contains personal data on an EU natural person regardless of where the company is based is based, or on any natural person anywhere if the company is EU based, it is subject to the GDPR.