This article is complementary to Importing BirdBase to eBird.
BirdBase codes do not strictly align with the eBird codes. It's not because they use different codes for the same country, but because the author of BirdBase provided a unique code for each distinct island or island group. BirdBase was less interested in political boundaries than biogeographic boundaries.
Here is a list of the known differences, and the recommended edits you will need to make to the code in Column L of the CSV file AFTER BB2eBird has been run.
The most frequently encountered issue is that IB is used in BirdBase to refer to the whole island of Borneo. IB would need to be changed to either MY (Malaysia) or ID (Indonesia)--depending upon which country was involved with each specific sighting.
Here are the other BirdBase codes that are not recognized by eBird:
AI for Andaman and Nicobar Islands (change to IN)
SS for the Lesser Sundas (change to ID)
CS for the Moluccas (change to ID)
SW for Sulawesi (change to ID)
TA for Sumatra (change to ID)
TP for TImor (change to TL for Timor-Leste)
SJ for Svalbard and Jan Mayen Islands (change to NO)
YU for Yugoslavia (change to appropriate country like Serbia)
MK for the Bismark Archipelago (change to PG)
PG for New Guinea--the island (change to ID if the sighting was in Irian Jaya and not Papua New Guinea)
CT for Canton and Phoenix Islands, which are treated separately from the rest of Kiribati (change to KI)
JT for Johnston Island (change to UM, United States Minor Outlying Islands)
MI for Midway Islands (change to UM, United States Minor Outlying Islands)
WK for Wake Island (change to UM, United States Minor Outlying Islands)
DB for Aldabra (change to SC for Seychelles)
RZ for Rodriguez (change to MU for Mauritius)
MS for the Leeward Islands, Anguilla thru Montserrat (change to code for appropriate island)
AN for the Netherland Antilles, all six islands (might have to break out AW for Aruba)