Ugarit Archive Metadata Schema

Any symbol can be used as an archive metadata property name, but here are some suggested ones, defined for the sake of interoperability.

Where possible, we have used the Dublin Core vocabulary, as it's a good fit for the kinds of things archive mode is designed for. Properties imported from Dublin Core are identified with a dc: prefix.

Some of these properties are automatically applied by the import process. However, if these properties are specified in the import manifest file, then the specified value from the manifest overrides the default.

Import properties

These are properties applied to an import object, rather than to an individual object in an archive.

Internal

These properties are all provided by the system itself, and must not be specified in an import manifest.

previous (hash)

The hash of a previous import. If there is no instance of this property, then this is the first import in a sequence. If there are more than one instances, then this is a merge.

contents (hash)

The hash of the imported archive manifest. This is probably not of much interest beyond the Ugarit internals.

mtime (number)

The UNIX timestamp of the import.

log (hash)

The hash of the import log file.

stats (alist)

An alist of import statistics.

manifest-path

The path to the manifest filename that was used for the import.

hostname

The hostname on which the import was performed.

Core object properties

These object properties apply usefully to almost anything in an archive.

import-path

The path the file was imported from, as taken from the import manifest file. (DEFAULT: The path from the manifest file)

filename

The name of the file, including the extension (if applicable), but not any directory path. This is usually the name the file had when it was imported (eg, the latter part of import-path), but if it was imported from some temporary file name while the system knows of a "proper" filename other than that, they may differ. (DEFAULT: The import path, minus any directory path)

dc:format

The MIME type of the file. (DEFAULT: A MIME type guessed from the file extension)

file-size

The size of the file. If it's a directory, then this is the sum of the sizes of the files within it, not including any directory metadata.

mtime (number)

The mtime of the file when it was imported, as a UNIX timestamp.

ctime

The ctime of the file when it was imported, as a UNIX timestamp.

dc:title

The title of the object. This should be a proper human-readable title, not just a filename, where possible.

dc:description

A longer description of the object.

Object properties for music

Music files should put the song title in dc:title.

dc:creator

The creator of the piece, generally the artist name.

dc:contributor

Some other contributor to the piece, other than the artist.

dc:publisher

The name of the publisher.

dc:created

The creation date, in YYYY-MM-DD form.

dc:subject

The name of the genre.

set:title

The title of the album.

set:index

Track number within the album.

set:size

Track count within the album.

superset:index

For multi-disk albums, the disk number.

superset:size

For multi-disk albums, the number of disks.

Object properties for photographs

Use dc:description for a description of the photo.

dc:creator

The name of the photographer.

dc:subject

Something in the photograph (names of photographed people or things, or more general keywords)

dc:spatial

The name of the place the photo was taken, or coordinates as a geo: URL.

dc:temporal

The name of the event the photograph was from.

dc:created

The creation timestamp of the photo, in YYYY-MM-DD format, optionally with a 24-hour UTC HH:MM:SS time.

Object properties for PDF/PS/ebooks

Use dc:title for the title of the work.

dc:creator

The name of the author.

dc:subject

A subject or keyword.

dc:created

The creation date in YYYY-MM-DD format.

dc:publisher

The name of the publisher.

dc:identifier

An ISBN, ISSN, or similar identifier, in URN format (eg: urn:isbn:0451450523).

dc:source

The original URL the thing was downloaded from.

Other useful Dublin Core properties

dc:alternative

An alternative title.

dc:extent

Size, duration, etc. Not the size of the file in bytes, but the duration of a recording, the size of an image in pixels, etc.

dc:language

The language of the object. en, en-GB, jbo, etc.

dc:license

A description of the license the file is under.

dc:accessRights

A space-separted list of names of groups that should be allowed to access the object, under some means of publishing all or part of an archive. public should refer to unrestricted access.

Please contribute!

The above are the conventions I have started to settle towards with the kinds of things I am using Ugarit archives for. If you use it for something else, please drop me a line and I'll be glad to help you choose a good schema, and publish the results here for others to share!