URN:lex

URN:lex is a proposed Internet standard for legal document identifiers written by Pierluigi Spinosa, Enrico Francesconi, and Caterina Lupo.  It is intended to coexist with (and provide important infrastructure for) more semantically-laden approaches like LegisLink and Citability.

The URN:lex proposal is here.

A growing set of worked examples can be found here.