6XX - Subject Access Points

"Use 6xx fields to provide subject access points. Most 6xx fields contain subject access points based on the thesaurus or subject heading system identified in the 2nd indicator or in subfield ǂ2. Subject access points are assigned to a bibliographic record to provide access according to established subject cataloging principles and guidelines. Use to describe the content of the cataloged resource. Genre/form terms describe what a cataloged resource is, not what it is about." -- BF&S

There is a lot involved in Subject Access -- entire courses in Library School are devoted to it. During October I am going to cover some basics to help you understand what is contained in various 6XX tags, but I want you to be aware that I am only scratching the surface of this huge topic.  

Subject headings come from specific schemes or thesauri. The second indicator of a 6XX tag tells you what scheme was used to create the heading in that tag:

2nd Indicator  Thesaurus
0	Library of Congress Subject Headings
1	LC subject headings for children's literature
2	Medical Subject Headings
3	National Agricultural Library subject authority file
4	Source not specified
5	Canadian Subject Headings
6	Répertoire de vedettes-matière
7	Source specified (with defined terms) in subfield ǂ2

The first indicator of 6XX tags is generally defined to specify how important the subject is in the work being cataloged (is it mostly about the specified subject, or only partly about it?). A blank in this indicator means "no information provided" and is the most common coding you will see.  

In the same way that 5XX tags are defined to contain specific kinds of notes, 6XX tags are defined to contain specific kinds of subject access points. Here are some examples:

• 600, 610, 611 tags contain various kinds of names (following the same structure as the corresponding 1XX tags) and are used when the work being cataloged is ABOUT those people, organizations, or meetings. 
• 630 tags contain uniform titles when the work being cataloged is ABOUT that title. 
• 653 tags are for "index term - uncontrolled"--these are terms that are not derived from a controlled thesaurus or subject heading system but which the cataloger felt would be of value to people beyond their own library. The 2nd indicator in this case tells you what kind of heading it is (name, subject, etc.)
• 69X these are subject headings for local use that are not thought to be of value to anyone beyond the library that created them.
   

Next week's post will focus on Topical subject headings (650 tags) and the following week we will look at Geographic subject headings (651 tags).