Hi Lori,
For one of the US retail major that I had worked for implemented the Auto Receipt feature using the ReceiptByCommodityCode.csv file. The file basically contained all commodity codes with the last column vale set to "AutoReceive" for the qualified commodities/items.
You might have to check if auto receiving is enabled for your site and you may contact ariba support for more details and impact analysis.
Regards
Vilas