Anonymized data is data which does not contain (or which has been cleaned of) all occurrences of personal data which can directly or indirectly identify a natural person. Anonymized data is not subject to the GDPR.
Please note: in case of indirect identification, data is not considered anonymous, Indirect identification can take place in different ways, e.g. by combining data, like a reference to a place of residence and a specific occupation. If anonymization implies that a data set is stripped from its analytical value, please consider not to offer the data for Open Access.