Last updated: 2003-03-06
The following codes are used in 856 $q (Electronic format type) at the Library of Congress in records used for American Memory and Global Gateway collections. The codes indicate the local digital format for complex objects when no single Internet Media Type applies. These codes are usually used for digital reproductions of materials originally in physical form, such as maps, printed volumes, sheet music, etc.
| Code value | Complex object format type | Notes |
|---|---|---|
| c | MrSID file + thumbnail | Supports "zoom" view. Used most often for maps. |
| h | Page-turner structure and page images (no text). Primary images expected to be convenient for on-screen viewing, i.e. 500-700 pixels wide. | Used for sequence of images. Also use for atlases and albums with primary display through page-turner. |
| s | Page-turner structure, page images, and machine-readable, searchable text | Text is usually marked up in SGML or XML. |
| t | Machine-readable, searchable text only. | Text is usually marked up in SGML or XML. Text may have links to illustrations. |
| p | Still image, several files at different resolutions, including thumbnail and screen-size reference image, with optional higher-resolution images. | Used primarily for pictorial items (photographs, prints, drawings, etc.). |
| g | Sequence of still images with thumbnails and optional captions. | Used for sets of pictorial images. Primary presentation as grid of thumbnails (contact sheet). Also use for atlases and albums with primary display through thumbnail grid. |
| m | Set of video files for a single item, in alternative digital formats, and possibly divided into segments | Used for video and motion pictures. |
| a | Set of audio files for a single item, in alternative digital formats | Used for sound recordings |
| u | URL | When digital objects are mounted at remote institutions (for example, for LC/Ameritech awardee collections) American Memory uses URLs specified in the 856$u. |
