Update : see extension v3 below (09 november 2016)

A proposed extension to describe Legislation within schema.org has been published at http://legal.eli-legislation-schemaorg.appspot.com/Legislation.
Additional material and use-cases description can be found on the extension page (examples still needed). The proposal was announced on the mailing-list.

The extension includes the following classes and enumerations :

• Legislation (subclass of CreativeWork) "A legal act or a component of a legal act (like an article).", with 24 new properties.
• LegislationObject (subclass of Legislation and MediaObject) "A specific object or file containing a Legislation. Note that the same Legislation can be published in multiple files. For example, a digitally signed PDF, a plain PDF and an HTML version."
• LegalValueLevel "A list of possible levels for the legal validity of a legislation."
• LegalForceStatus "A list of possible statuses for the legal force of a legislation."

The diagram below gives an outline of the extension :

This extension proposal comes with suggestions to improve the core schema :

• Add "Legislation" as subclass of CreativeWork #1154 Add "Legislation" as subclass of CreativeWork in the core schema
• Create an inverse property for schema:citation (schema:citedBy) #1031 Create inverse property of schema:citation
• Improve the definition of MediaObject  #1153 Improve the definition of MediaObject
• Improve definition of property "encodingFormat" (vs "fileFormat") #1155 Improve the definition of encodingFormat
• schema:encodesCreativeWork should be declared inverse of schema:encoding #1030 encodesCreativeWork should be made inverse of encoding
• per-Property, per-enumerated-value pages should show acknowledgements (and multiple should be possible) #1022 allow proper credits to properties and enumeration
• Broaden the range of schema:version from Number to Text #1151 broaden the range of property schema:version to allow Text
• Add a generic "relatedWork" property to relate CreativeWork together #1152 add a generic property "relatedTo" to relate CreativeWorks

This extension is adapted from the European Legislation Identifier (ELI) ontology. The ELI development is driven by national legal publishers of some European countries, and by European institutions, all aiming at identifying, describing and linking legislation on the web. For more information on ELI, see the ELI register.

We would love to get feedback from the community on this proposal to improve the description of legislation with schema.org. Our objective is that this proposal be integrated either as a hosted extension, or even in the core.