PLEASE NOTE: Lesson 4 is currently being revised.  Please be advised that the federal government has done away with the "DUNS" number and now requires all applicants to register for a UEI (Unique Entity Identifier) through sam.gov. In this delightful bureaucratic restructuring, what was once called the "Opportunity Number" is now called "Assistance Listing". You do not need to take action on this one.  It's simply an update on vocabulary.  The video lesson says that the Assistance Listing number is the unique number associated with a particular grant.  It's a code you can put into the grants.gov search bar to find a specific grant profile.