...
EXAMPLE: The papers of My Best Friend include travel diaries, family scrapbooks, personal and professional correspondence, photographs, 23 audiotapes and 45 disks.
With addenda, you should also discuss whether the material you will be working with is the same or different from that in the original collection. Is it the next 10 years of board binders? Is it A/V that was not donated before? Does it come from a different office of the organization or the attic of a board member?
When adding addenda, it is important to write a sentence or more in the top-level scope note articulating what you are doing and why. If you are doing a lot of renumbering, this can get kind of complicated. Writing this out in the processing plan can help clarify what the work is (you may want to complete the rest of the processing plan and then write this statement.)
EXAMPLE: From Additional records of the Women's National Farm and Garden Association:
Additional material received between 2012 and 2015 (accession numbers 2012-M174, 2015-M165, 2015-M197) were added to the collection in June 2018. These materials are housed in #18.1-20.4, E.2. Folders are listed in intellectual, not numerical, order.
EXAMPLE: From Freda Kirchwey papers (a very complicated one!)
The collection was first arranged and processed with a National Endowment for the Humanities grant in 1979. Material was arranged and folders were numbered sequentially (#1-383f+). Another group of material (accessions #80-M210, 81-M149, and 81-M201) was added to the collection in 1981, and was further sequentially numbered (#384-434). This addenda was described in the finding aid after the original material, as if in a separate series. In 2016, two later accessions (1999-M86 and 2000-M15) were added to the collection. Each of these groups of material is housed together. Also in 2016, the entire collection was reboxed and renumbered. The original group of papers is now numbered #1.1-26.7, the 1981 addenda is #27.1-29.19, the 1999 addenda is #30.1-32.5, and the 2000 addenda is #33.1-33.21. The three groups of addenda are now listed intellectually within the finding aid with the series in which they belong. A copy of the original inventory with original numbering is in the first box of the collection. Series VI, Photographs, was not renumbered, as some of those photographs had already been digitized.
At the time of original processing, parts of the collection were closed to research. In 2009, some restricted material was added back into the collection. Folders that contain this material are noted as such in the inventory.
Appraisal and research strengths:
...