Most of the sources used to prepare the lineage and honors entries are located in the document collection of the Air Force Historical Research Agency (AFHRA) at Maxwell AFB, Alabama. The most important sources are the histories that Air Force organizations at all echelons periodically prepare and send to the Agency under the auspices of the Air Force History Program. The Agency maintains organizational record cards and emblem records as working papers to provide essential information. The Agency also collects indispensable primary source documents, including G-series special orders, operations plans and reports, organizational directories, Department of the Air Force manpower and organization numbered letters, and similar records. Unfortunately, even with all the available information, the historians could not always ascertain specific facts. These entries are subject to revision in the light of evidence that may be discovered or become available in the future.