I think here we should mention for the novice that RG in front of a number means Record Group. The RG75 is the record group for Records of the Bureau of Indian Affairs. Microfilm publications are divided into two series identified by "M" and "T" numbers. Usually an "M" publication reproduces an entire series of records and has an introduction describing the origin content and arrangement of the records filmed. Descriptive pamphlets are available for most "M" publications. The pamphlet contains the publication's the publication's introduction and roll-by-roll breakdown of the records filmed.

[originally posted 26 May 1999]