That is incorrect information you got there from DL. In the February 1999 FFL newsletter the ATF sends out to all dealers this topic was specifically addressed and here was thier response:
ATF has been asked to comment on whether
functions such as the Ducks Unlimited or Friends
of the NRA dinner banquets would constitute an
event under 18 U.S.C. § 923(j) and 27 CFR §
178.100.
As you are aware, the Gun Control Act of 1968
(GCA) generally requires Federal firearms
licensees to engage in the business from the
location specified on their license. However, the
GCA allows Federal firearms licensees to conduct
business temporarily at a location other than the
location specified on the license if such temporary
location is a gunshow or event.
The GCA defines a gunshow or event as a function
sponsored by any national, State, or local
organization, or any affiliate of such organization
devoted to the collection, competitive use, or
other sporting use of firearms in the community.
18 U.S.C. § 923(j). Therefore, Federal firearms
licensees may conduct business temporarily at
such events provided they are sponsored by a
qualifying organization as defined in 18 U.S.C. §
923(j) and 27 CFR § 178.100.
Licensees must remember that these gunshows or
events must be located in the State where they
currently have a licensed business premises, and
they must record the locations of any firearms
transactions occurring at these events in all their
required records. Furthermore, NICS checks must
be conducted on these transfers in the same
manner as the licensees conduct such checks from
their licensed premises.