Before revision:  In the differential pricing scheme, Internet Service Providers (ISPs) can exempt data traffic charges for accessing content from certain CPs or applications (zero-rated) and apply regular charges for accessing content from other CPs.
After revision:  In the differential pricing scheme, Internet Service Providers (ISPs) can exempt data traffic charges for accessing content from certain CPs or applications (zero-rated) while no exemption is on content from other CPs.