If an activity is created or delegated for another responsible person who does not have access to linked objects (cases, etc.), the CRM issues a corresponding message indicating this. In this case, you can grant read access to this activity, but without access to the linked object.
If read permission is not granted, the person actually “responsible” will only see the corresponding entries in their Entry Portal as asterisks (*****). In the message form that announces the delegation, for example, the subject of the activity can always be read as plain text so that the recipients at least know the subject even without read permission. The user or recipient can mark this activity, for which they do not have read permission, in their Entry Portal and generate a message. The creator or delegator is automatically entered as the recipient of the message. This allows the user to inform this person that they do not have read permission.