https://postalpro.usps.com/4117/rss.xmlSingleSource ACS™ Postsen https://postalpro.usps.com/acs/singlesourceACStechguide.pdf This guide is a technical reference for SingleSource ACS. Includes how ACS works, participation requirements, and fulfillment files. Fri, 18 Oct 2019 00:00:00 -0400 https://postalpro.usps.com/acs/singlesourceACStechguide.pdf This guide is a technical reference for SingleSource ACS. Includes how ACS works, participation requirements, and fulfillment files. Fri, 18 Oct 2019 00:00:00 -0400