What the act allows
Essential, important and other entities may voluntarily exchange relevant cybersecurity information in order to prevent, detect, respond to or recover from incidents [1]. This can take place within communities of entities and with their suppliers, on the basis of agreements on the sensitivity of the information [2].
Registration
If you fall under the Cbw, you also pass on for the national register participation in and withdrawal from such an information-sharing arrangement [3], and you report changes without undue delay or in any event within two weeks of the date of the change [4].
What you do with information you receive
If you receive targeted security advisories or threat information, for example from a CSIRT or a supplier, you assess whether your measures need to change and record that [5]. The CSIRT itself also exchanges information with entities and communities of entities [6].
In practice
Share indicators and attacker methods, not customer data. If the information contains personal data, such as names or email addresses, limit it to what is necessary.