a - Language material
Code a indicates that the content of the record is for non-manuscript language material. Use for microforms that are basically textual in nature, whether reproductions from print or originally produced. Manuscript language material uses code t.

c - Printed music
Code c indicates that the content of the record is for printed music or a microform of printed music.

d - Manuscript music
Code d indicates that the content of the record is for manuscript music or a microform of manuscript music.

e - Cartographic material
Code e indicates that the content of the record is for non-manuscript cartographic material or a microform of non-manuscript cartographic material. This code is used for maps, atlases, globes, digital maps and other cartographic items.

f - Manuscript cartographic material
Code f indicates that the content of the record is for manuscript cartographic material or a microform of manuscript cartographic material.

g - Projected medium
Code g indicates that the content of the record is for a motion picture, videorecording, filmstrip, slide, or transparency. All of these media are intended for projection. Material specifically designed for overhead projection is also included in this category.

i - Nonmusical sound recording
Code i indicates that the content of the record is for a recording of nonmusical sounds (e.g., speech).

j - Musical sound recording
Code j indicates that the content of the record is for a musical sound recording.

k - Two-dimensional nonprojectable graphic
Code k indicates that the content of the record is for a two-dimensional nonprojectable graphic. Examples are activity cards, charts, collages, computer graphics, drawings, duplication masters, flash cards, paintings, photonegatives, photoprints, pictures, postcards, posters, prints, spirit masters, study prints, technical drawings, transparency masters, and reproductions of any of these.

m - Computer file
Code m indicates that the content of the record is for a body of information encoded in a manner which allows it to be processed by a computer. The information in the computer file may be numeric or textual data, computer software, or a combination of these. Although a file may be stored on a variety of media (such as magnetic tape or disk, punched cards, or optical character recognition font documents), the file itself is independent of the medium on which it is stored.

o - Kit
Code o indicates that the content of the record is for a mixture of various components issued as a unit and intended primarily for instructional purposes. No one component is identifiable as the predominant component of the item. Examples are packages of assorted material, such as a set of K-12 social studies curriculum material (books, workbooks, guides, activities, etc.), packages of educational test materials (tests, answer sheets, scoring guides, score charts, interpretative manuals, etc.), or a laboratory kit.

p - Mixed material
Code p indicates that the content of the record is for two or more forms of material that is usually related by virtue of its having been accumulated by or about a person or body. No one form of material in the group is emphasized or predominates. The intended primary purpose is other than for instructional purposes (i.e., other than the purpose of those materials coded as o--Kit). This category includes archival and manuscript collections of mixed forms of materials, such as language material, photographs, and realia.

r - Three-dimensional artifact or naturally occurring object
Code r indicates that the content of the record is for a three-dimensional artifact or a naturally occurring object. Examples are man-made objects such as models, dioramas, games, puzzles, simulations, sculptures, and other three-dimensional art works, exhibits, machines, clothing, toys, and stitchery. It also includes naturally occurring objects such as, microscope specimens (or representations of them) and other specimens mounted for viewing.

t - Manuscript language material
Code t indicates that the content of the record is for manuscript language material or a microform of manuscript language material. This category is applied to items for language material in handwriting, typescript, or computer printout including printed materials completed by hand or by keyboard. At the time it is created this material is usually intended, either implicitly or explicitly, to exist as a single instance. Examples include marked or corrected galley and page proofs, manuscript books, legal papers, and unpublished theses and dissertations.