The link I provided says that pseudonymous data can be used to hide personalized data.

If you are a DPO, you can see the appeal and benefits of pseudonymization. It makes data identifiable if needed, but inaccessible to unauthorized users and allows data processors and data controllers to lower the risk of a potential data breach and safeguard personal data.

GDPR requires you to take all appropriate technical and organizational measures to protect personal data, and pseudonymization can be an appropriate method of choice if you want to keep the data utility.

The owner of lemmy.one can use tk338@lemmy.one to map it to an IP and/or email address. This becomes now personally identifiable data. But other instance owners can't map it to any personalized data, so it is basically "anonymized data" for them.

You just have to provide a way to either

• To delete personally identifiable data
• Unlink the personally identifiable data from the pseudonymized data on your local instance.

Disclaimer, IANAL, YMMV, yaddy, yadda,...