For an overview of MARC records see Understanding MARC Bibliographic Machine-Readable Cataloging
This manual uses DACS as its primary standard: Describing Archives: A Content Standard. (Chicago: Society of American Archivists, 2013). DACS was first implemented at Houghton in January 2007 for all new finding aids and for new MARC collection-level records. It was implemented for accession records as of September 1, 2006. In September 2013 – June 2014, this manual was updated to DACS 2013.
Deviation from DACS: It should be noted that DACS states on p.4: "While in no way contradicting the value of standardization, such words and phrases recognize that uniform rules for all types of descriptions are neither possible nor desirable, and they encourage institutions to develop and document a description policy based on specific local knowledge and consistent application of professional judgment. Furthermore, it is recognized that a particular data element may be formulated differently depending on the intended output system."
The hierarchy of surrogacy: The MARC collection-level record is only a summary or abstract of information contained in the finding aid of the collection; the finding aid itself is a surrogate of the collection materials. This is sometimes called the "hierarchy of surrogacy" (term credited to Steve Hensen). It is also called the pyramid. A finding aid should be prepared and available for referral prior to beginning the work on the MARC record. The collection-level record is made after the finding aid for the collection is finished. Most of the fields listed below will already be determined from the text in the finding aid. Some may be simply copied into the MARC record directly from the finding aid but some should be edited down in size. The DACS manual provides a good cross-walk for how the fields in MARC relate to the sections created in a finding aid. See also the Houghton processing manual for further assistance.
Square brackets: DACS specifies that it is best not to use square brackets in any type of output. We will deal specifically with the use of square brackets in specific fields below.
Abbreviations: DACS specifies that it is best not to use abbreviations in any type of output.