The 2012 edition features two impressive editorial enhancements and more than 9,000 value changes.
The first is the addition of a new section listing the Colombia Consular overprints using the service established by established by the Sociedad Colombo-Alemana de Transportes Aereos (SCADTA).
The second editorial enhancement is the reorganization of the listings for the two die types of the 2¢ 1903-08 Washington Shield stamps. The type I perforated and imperforate stamps are now Scott 319 and 320, respectively, and the type II stamps are Scott 319F and 320A, respectively.
Error collectors will be pleased to note the addition of 20 new errors, some of which are carried over from the 2012 Vol. 1. Among the more impressive mistakes is a post-printing foldover on a pane of 8¢ Eisenhower stamps (Scott 1394) that yielded four new errors, including stamps printed on the gummed side, and stamps with all three colors and tagging missing.