This section contains information relating to the physical description of the resource.
physicalDescription has the following components:
Physical description of a physical piece belongs in Source metadata.
A note on duration and extent for time-based media: For film, video, and audio, the duration of the content is recorded twice. Because the duration of the content, often expressed in minutes, pertains to the intellectual work itself (as opposed to a particular manifestation of it on videotape or in a digital file), it is recorded first in Descriptive metadata, as EXTENT. (Information about a particular manifestation of the work is recorded in Source or Technical metadata.) In Descriptive metadata, a film's extent might be described as "99 minute(s)."
Second, the duration of a particular manifestation is described in Source or Technical metadata as a timecode, in the DURATION element. For example, a title consisting of two videocassettes, each 60 minutes in duration, would have a duration of two hours, or 02:00:00:000/1000. (Do not confuse this timecode value with the actual timecode found on the physical piece; information about that timecode, such as type of timecode and how it is recorded on the media, is recorded in the TIMECODE element.)
The extent of the physical item, in terms of physical pieces, is recorded in the EXTENT elements, in Source metadata. For example, "2 videocassette(s)."
The actual length (linear measure) of the physical piece is recorded in the LENGTH element, in Source metadata. For example, "232 ft."
For digital video and audio, the breakdown of content, in terms of segment start and stop times, is handled in the structure map.
Presentation Format - Form
A designation of a particular physical presentation of a resource.
form has the following components:
Presentation Format - Form - Value
Terms may be taken from the Library of Congress' Source Codes for Form
Presentation Format - Form - Term source
A list of authorities is maintained at: www.loc.gov/marc/sourcecode/form/formsource.html.
Presentation Format - Extent
A statement of the number and specific material of the units of the resource that express physical extent. extent may be used with electronic resources, e.g. digitized collection of slides, to show how many slides constitute the resource.
extent has the following components:
Presentation Format - Extent - Extent Unit
image(s); page(s); piece(s); second(s); minute(s); hour(s); digital file(s); sheet(s); other
Presentation Format - Extent - Extent
A positive integer
Presentation Format - Internet Media Type
An identification of the electronic format type, or the data representation of the resource. The value is taken from a controlled list, especially from the Internet Media types (MIME types) (see: www.iana.org/assignments/media-types/index.html for a complete list).
This element provides the Internet Media type for the display objects only. Other digital instantiations are documented in Technical metadata; analog instantiations are documented in Source metadata. Electronic format types specified here may include text/html, ASCII, Postscript file, executable application or JPEG image.