As of this writing, some units continue to file accession-type call numbers in various card/paper shelflists within various departments. Paper slips or cards are filed in numerical order to hold a place for each unique number on the shelf. Partial list of accession number files:
a. [Obsolete] Special folio call numbers. For certain types of oversize books and serial titles in SML. File location: SML Catalog Dept. Current practice: Folio in 852 k, followed by LC call number with the standard local modifications. For specific arrangement see: Oversize.
b. Microform. For microform holdings in the SML Microform collection. There are separate files for service copy microfilm monographs, service copy microfilm serials, master negative copy microfilm monographs, master negative microfilm serials, dissertation microfilm (service copies), monograph microfiche and serial microfiche. (All microfiche holdings are service copies) There are also separate files for school and departmental microform and microfiche holdings for titles cataloged by SML. File location: SML Catalog Dept.
NOTE: microfilm newspapers are assigned an Old Yale call number for newspapers and subarranged by place following the Cutter-Sanborn table rather than the LC table.
c. [Obsolete] Visual materials. Used for titles in visual materials and electronic resources formats cataloged for the Arts Library. VIM followed by accession number. Current practice: LC call number with the standard local modifications.
Many Yale library locations also maintain files of non-LC call numbers. Generally these files are separately maintained; "union catalog" rules do not apply to non-LC call numbers, but within each file the basic shelflisting objectives are still observed: any non-LC call number assigned must be unique and inserting it must not disrupt the integrity of the local file.