Commons:License meta-tags

This page is presently inactive and retained primarily for historical interest. This proposal was abandoned for technical reasons like bugzilla:5527. It was superseded by Commons:Tag categories, which also has been abandoned. This page should be kept for reference for a while.

License meta-tags are an attempt to make license tags and categories more "machine readable". This will hopefully benefit tools like OrphanImages and UntaggedImages, which currently work on a rough approximation of what is, and what is not a license or deletion tag, a maintanance category, etc. This page describes an experimental guideline for tagging license templates, maintanance categories, etc, as discussed on the village pump. Comments are welcome on the talk page.

Meta-tags should be placed in templates to mark a basic property of the template (like being a license tag). The number of meta-tags should be very limited - there should only be a small, well defined set of them, ideally identical in several wikis. Creating new meta-tags at a whim would defeat their purpose, namely being well-known identifiers for the meaning of templates and categories. Also, to keep things simple, meta-tags should not be nested.

Side note: Generally, nesting templates should be avoided if possible. However, for the meta-tags to work properly, they have to be nested into the license templates, and must not be inside <noinclude> tags. This is because of the way template-links are stored in the database.

NOTE: some bold people will soon start to apply meta-atags to templates. This should be done carefully, step by step, to give people to opportunity to comment. Suggestions are welcome on the talk page!

PENDING: think about RDF for meta-tags. is it really possible without having tags for every possible combination?

Available Meta-Tags

Meta-tags for license templates:

• {{License tag}}: should be contained in all license tags, to mark them as such.
• {{License problem}}: for tags indiating license problems, like {{Unknown}}, {{No source}}, etc

More fine grained meta-tags that represent license requirements are useful for finding images fit for publication elsewhere:

• {{License attribution}}: for marking licenses that require attribution
• {{License share-alike}}: for marking licenses that have a share-alike policy
• {{License full-text}}: for marking licenses that require the full text of the license to be distributed with the work
• {{License custom}}: for license tags that can be customized, like {{CopyrightedFreeUseProvidedThat}}. Since the actual requirements may differ, this should be assumed to require at least attribution, and perhaps also share-alike.
• {{License non-free}}: for non-free license tags, like {{Copyrighted by Wikimedia}} or for fair use on wikis that accept that.
• {{Usage restriction}}: for tags that imply a non-license restriction, such as {{Seal}}.

More meta-tags, not directly related to licenses

• {{Deletion tag}}: should be in all tags that mark something for deletion. This makes it easy to hide material that may be questionable.
• {{Meta category}}: for marking non-topic categories (not templates). This is useful for tools like UntaggedImages, because it makes it easy to find out which images are not categorized by topic. (Note: as opposed to the other meta-tags, this is probably only useful on Commons, where images are required to be categorized by topic).

Examples

• {{GFDL}} would be tagged with {{License tag}}, {{License attribution}}, {{License share-alike}}, and {{License full-text}}
• {{Cc-by-sa-2.5}} would be tagged with {{License tag}}, {{License attribution}}, and {{License share-alike}}
• {{CopyrightedFreeUseProvidedThat}} would be tagged with {{License tag}} and {{License custom}}
• {{PD-old}} would be tagged with {{License tag}}
• {{No source since}} would be tagged with {{License problem}}
• {{Fair use}} would be tagged with {{Deletion tag}}
• {{Nazi symbol}} would be tagged with {{Usage restriction}}
• Category: Redundant, Category:Disambiguation, etc, would be tagged with {{Meta category}}

Note that the meta-tags should not be in <noinclude> tags. They need to be included in the image description page, so they can be accessed directly in the database. Also, special care must be taken to make sure new license tags get the correct meta-tags.