In many of the Avene Sunscreens you will see the label SPF/PPD < 3, that in many cases can cause confusion.
In the end, this only means that the SPF of the product divided by its PPD is equal or less than 3.
In the case of the SPF50+ Sunscreens, for example, their PPD is equal or higher than 16.666. As these Sunscreens substituted the SPF60 nomenclator, we can estimate that the PPD of the 50+ Sunscreens is at least 20.