The instructions for product position
pr<productIndex>ps is the following. What is the use case of the product position parameter in the google measurement protocol? Where does this show up in google analytics as I haven't been able to see it within google analytics.
The product's position in a list or collection. Product index must be a positive integer between 1 and 200, inclusive. For analytics.js the Enhanced Ecommerce plugin must be installed before using this field.