Machine Tags (aka Triple Tag) - Machine Tags I used and loved

I'm using some machine tag in my various projects. Sometimes they are used by some other people/project. In this page you can find a summary of practices and the list of namespace I'm using. Some are widely used like license: or language: but there are some experimental like linkfingerprint:.

A machine tag is composed of a namespace (MUST), a predicate (MUST) and an (OPTIONAL) value. Machine tag is sometime called triple tag due to its format.

Machine tags (MachineTag) are just standard tag with extra information to extend the information in the tag. They are called machine tags because there are often use by program to get extra information from the tagged work.

For more information about machine tag : http://www.flickr.com/groups/api/discuss/72157594497877875/

Machine Tag namespace in use with their description

• Language tag to specify the language in use for the tagged content - MachineTagLanguage
• Computer Language tag to specify the computer language used tagged content - MachineTagCSLang
• License tag to specify in the license in use for the tagged content - MachineTagLicense
• Used by the Free Archive project - MachineTagFreeArchive
• Used to rate Free Software project - MachineTagFsRating
• Link Fingerprint and/or Digital Signature (idea from IDs-URI-linkfingerprints) - MachineTagLinkFingerprint
• Book tag to add useful machine-readable information about books - MachineTagBook
• Geo tag to geographically localized tagged - MachineTagGeo
• Taxonomic/Taxonomy machine tags - botany and biology classification - MachineTagTaxonomy
• Common Vulnerability and Exposure (CVE) - [[MachineTagCVE?]]
• Traffic Light Protocol (TLP) - [[MachineTagTLP?]]

Visual Explanation

We can see in this example all the information linked to the URL to describe a free software project including its rating, computer language and free license used. Readable by human and machine in one shot.

FAQ about Machine Tags

Who is deciding about a name space?

No one, that's the magic (sometime the disillusion) of name space : Everyone can take a name space that can be shared with other people. There are nice example like the "Burning Man" machine tags where you can see there is no specific restriction. But the flexibility of allocation allows people to use their own and see if the other users will use it or not. The success of a name space is based on its use.

What's the difference between Machine Tags, RDFa and microformats http://microformats.org/?

The objective of RDFa or microformats are somehow similar to Machine Tags but are mainly targeting the (X)HTML format. Machine tags are often used standalone to reflect a specific classification of a page. RDFa or microformats are inherently attached to a link or the data encapsulated in a markup language. Microformats is mostly using the class attribute to describe the data. RDFa is using the rel attribute with a properly defined XML namespace to describe the data.

Machine tags can express the same information or even sharing the same namespace of RDFa or microformats. Machine tags are just used as a readable tags format requiring a mixed approach of classification between human tagging and machine-readable tags while not really focusing of specific document format.

Is there any good parser for machine tags?

• cs_lang:python license:perl - machinetag python parser made by aaron
• cs_lang:javascript - Javascript and machine tag

Tags: tagging tag folksonomy classification reference machinetag machinetags triple_tag