'Agency of Record' is just a term used to identify the
advertising agency that a company uses.
While it's often used incorrectly, it should only be applied in
cases where a company has one agency handle all of it's
advertising. e.g. You wouldn't say that Wieden+Kennedy is Nike's
agency of record because Nike use other agencies throughout the
world. DDB Paris handles much of their advertising in France. You
could say, however, that Wieden+Kennedy is the agency of record for
CareerBuilder.com as W+K is the only advertising agency they
use.