Create a general task that can be assigned to a customer. Instead of having to use a customer approval task (or modify the customer approval task so that the reject can be removed and the approve renamed to something else)
Basically this is used for providing additional information during the life cycle of a request.
The request form provides the basic info, then depending on some rules additional info is required so a second task goes to the customer to fill in a second form.
It is important to have the Save for Later feature on this form as well. So that a very detailed form can be saved and not filled out in one go.
This is very useful in cases of multi-phased requests where not all the information is available at the beginning when logging the request.