ISOO has posted Notice 2020-02, "Transmitting Classified Information," which reminds agencies of requirements they must meet for sending classified information through the U.S. Postal Service (USPS) or by means of commercial carriers. The notice can be found here. Cleared contractors under DoD cognizance are additionally reminded that they should verify that the carrier being used is still listed on the ISOO website prior to shipment of classified material. The list of carriers who meet the requirements of 32 CFR Part 2001 and the NISPOM can be found at https://www.archives.gov/isoo/faqs#what-is-overnightcarriers.