Questions related to retention period property

The current definition of the property states 'A temporal period which the dataset is available for secondary use'.

Several questions related to the property retention period arise:

• Is this retention period about the dataset itself or the retention period when the data is in the hands of a data processor? (unclear due to unclear range)
• Is this period based on law?
• And does it depend on a particular purpose?
• How to determine the retention period? Should there be a minimum & maximum retention period?

This question relates to the unclear range of the property as stated in #5