Nevermind, I found it in the configuration documentation for Magento 2. Link here for anyone wondering.
Does anyone have any information on how the "Modification" setting in the SKU Settings section of the Configuration wizard works? I know we will have multiple listings for a single SKU within Walmart, and I am trying to plan for how this will be handled. The getting started guide here only says to put in the settings, but does not elaborate on what this does, how it works, or what acceptable "Postfix" values would be.