Lex (URN)


lex is a URN namespace, a type of Uniform Resource Name, that allows accurate identification of laws and other legal norms.
LexML Brasil and Italy already do an official use of the URN LEX standard draft v0.9, as a namespace for sources of law.

Syntax

The identifier has a hierarchical structure as follows:
where NSS is the Namespace Specific String composed as follows:
where:
Illustrative examples of sources of law identifyed by lex URNs:

 urn:lex:it:stato:legge:2003-09-21;456 
 urn:lex:fr:etat:lois:2004-12-06;321 
 urn:lex:es:estado:ley:2002-07-12;123 
 urn:lex:ch:glarus:regiere:erlass:2007-10-15;963 
 urn:lex:eu:council:directive:2010-03-09;2010-19-UE 
 urn:lex:us:federal.supreme.court:decision:1963-03-18;372.us.335

Concrete examples

Real URN LEX resolver at Brazil, the country where URN LEX was adopted since 2009, with the portal:
URNs are used as unique identifiers, like in, for example, to identify a book by its ISBN - so, the URN is also nominated as "public ID". In that kind of public utilization, the need for a central authority as unique and necessary URN-resolver, is a problem. In that context, the identifier's user must to query the authority about the correct ID, from some object's metadata, like year or title. IDs like ISBN, that need a central authority are also named "opaque IDs".
A common use of Lex URNs, by other hand, is to express transparent identifiers, that can be built up by simple rules or inferences from basic metadata. Example: the Brazilian Lex URN is used for both, legislative and case law unique and universal identifier, using rules of formatting and abbreviation of the authority's name, the publication date, and the local identifier.
URN schemes where each URN is also a transparent identifier, can be used in distributed URN-resolution systems; and the URNs can be created in absence of these systems, even before to the recording in these systems.