Author Only adventures are adventures for Adventurers League (AL) that are written by individuals that can only be run in their own campaigns as Adventurers League official until sold on DMsGuild.
Robert Adducci mentions on his Patreon page that he is an Adventurers League administrator and as a result was given the privilege of writing Author Only adventures.
Are Author Only adventures any different than Convention Created Content (CCC) adventures? (i.e. Is the path to writing an adventure always associated with running a convention?) Have there ever been Author Only adventures written by non-AL administrators?