§ 43 DSG NRW
Distinction between facts and personal assessments
(1)The controller shall, in the course of processing, distinguish as far as possible whether personal data are based on facts or on personal assessments. For this purpose, he or she shall, insofar as this is possible and appropriate in the context of the respective processing, mark appraisals based on personal assessments as such. It must also be possible to determine which body maintains the records underlying the appraisal based on a personal assessment.