Field name: Your choice (default = “Subject”)
DC Element: Subject
The topic of the content of the resource. You can use subject terms taken from a controlled vocabulary (recommended best practice) or keywords that you devise yourself to describe the topic of the resource. Generally, this field will contain terms that describe what is depicted in the image, or terms that describe what a text is about.
Providing subject terms for images can be tricky. You may want to be careful about providing terms for things or topics that are not actually visible in the picture. The Library of Congress provides these guidelines:
Catalogers should consider some additional questions when trying to decide which subjects to index. How historically significant is the subject matter of the images? Is the subject matter widely depicted, or are there novel aspects which are rarely found in pictorial collections? If a subject is not prominently or clearly shown in an image, can it be omitted in indexing because it is better represented elsewhere? How does the material relate to other collections in the institution? How can such significant relationships be highlighted through consistent description and indexing from one collection to the next? Does a group of images demonstrate that the creator had a particular point of view or message in mind, thus providing a rationale for indexing for the context as well as the content? It is often important to remember that the images being cataloged may, in fact, be unique primary evidence of a particular time and place.
For more advice on indexing images, see the Library of Congress TGM-1 Introduction.
Examples of field names:
- Subjects
- Common names (field for taxonomy)
- Keywords
- Style (field for art/architecture)
- Building type
Examples of data:
- American glasswort
- Workers’ compensation
- Bridges
- Markets–Washington (State)–Seattle (full Library of Congress Subject Heading style)
Recommended format:
- Use a consistent form for topics (same topic, same form). See controlled vocabularies below.
Use 2 hyphens with no spaces on either side between subdivisions for full LCSH:
- Indians of North America–Northwest, Pacific–Structures
If there is more than one term or phrase in the subject field, separate by <br>:
- Workers’ compensation<br>Social security
Recommended controlled vocabulary:
- Library of Congress Thesaurus for Graphic Materials I: Subject Terms (TGM1): List created by LC for indexing visual materials, such as photograph collections. The list contains over 6300 terms and is compatible with the larger LCSH file (see below), which can be used to supplement TGM1.
- Library of Congress Subject Headings (LCSH): List maintained by LC and other libraries. This is a large file of subject terms (over 1/4 million as of 1999) and covers many different subject areas and disciplines. It is also the authority file used by the UW Libraries Catalog and many UW Libraries digital projects. You can find LCSH terms in the Library of Congress Authorities by doing a Subject Authority Heading search. Library catalogers have been trained to construct complete LCSH headings with subdivisions, but you could use LCSH terms as simple descriptors without subdivisions.
- Art and Architecture Thesaurus (AAT): List maintained by the Getty Institute. “The AAT is a structured vocabulary containing around 125,000 terms and other information about concepts. Terms in AAT may be used to describe art, architecture, decorative arts, material culture, and archival materials. The coverage of the AAT ranges from Antiquity to the present, and the scope is global.”
- Terms or descriptors from a thesaurus used by an index in a particular field can be another source for controlled vocabulary. For instance, ERIC descriptors could be useful for education-related resources or Chemical Abstracts terminology might be most appropriate for a specialized chemistry collection.