Advanced Commands help you specify how you want your products to show up. For example, to remove all images from your product feed, you would use deleteAttribute featured_imgurl.
If you want to view all of the Advanced Commands, go here.
You will find the updated advanced commands and information about product feed customization options for attribute mapping here.
Please note that if you want to view the list of available attributes at any given time, create a new feed as “Product list raw export” feed from select merchant type.
With the raw feed, you will be able to understand which products attributes are present on your eCommerce platform. You will need these attributes to use the advanced commands for feed optimizations.
