feat: add unitsml urn document draft

metanorma.yml

@@ -4,6 +4,7 @@ metanorma:
     files:
       - sources/asciiunits/document.adoc
       - sources/unitsdb/document.adoc
+      - sources/unitsml-urn/document.adoc
       # - sources/unitsml-guide/document.adoc
       # - sources/unitsml-incorporation/document.adoc
       # - sources/unitsml-ubl-ndr-subset/document.adoc

sources/unitsml-urn/document.adoc

@@ -0,0 +1,51 @@
+= CalConnect Standard: UnitsML URN namespace specification
+:title: UnitsML URN namespace specification
+:docnumber: 36811
+:copyright-year: 2025
+:doctype: standard
+:edition: 1
+:status: committee-draft
+:revdate: 2025-03-25
+:published-date: 2025-03-25
+:technical-committee: UnitsML
+:fullname: Ronald Tse
+:surname: Tse
+:givenname: Ronald
+:affiliation: Ribose Inc.
+:imagesdir: images
+:mn-document-class: cc
+:mn-output-extensions: xml,html,pdf,rxl
+:local-cache-only:
+:data-uri-image:
+
+include::sections/00-foreword.adoc[]
+
+include::sections/00-intro.adoc[]
+
+include::sections/01-scope.adoc[]
+
+include::sections/02-normrefs.adoc[]
+
+include::sections/03-terms.adoc[]
+
+include::sections/04-principles.adoc[]
+
+include::sections/05-elements.adoc[]
+
+include::sections/06-composite.adoc[]
+
+include::sections/07-composite-normalize.adoc[]
+
+include::sections/08-urn.adoc[]
+
+include::sections/09-namespace-considerations.adoc[]
+
+include::sections/10-community-considerations.adoc[]
+
+include::sections/11-security-considerations.adoc[]
+
+include::sections/12-iana.adoc[]
+
+include::sections/99-bibliography.adoc[]
+
+include::sections/a1-ebnf.adoc[]

sources/unitsml-urn/sections/00-foreword.adoc

@@ -0,0 +1,35 @@
+
+.Foreword
+The Calendaring and Scheduling Consortium ("`CalConnect`") is a global
+non-profit organization with the aim to facilitate interoperability of
+collaborative technologies and tools through open standards.
+
+CalConnect works closely with international and regional partners,
+of which the full list is available on our website
+(https://www.calconnect.org/about/liaisons-and-relationships).
+
+The procedures used to develop this document and those intended for its
+further maintenance are described in the CalConnect Directives.
+
+In particular the different approval criteria needed for the different
+types of CalConnect documents should be noted. This document was drafted in
+accordance with the editorial rules of the CalConnect Directives.
+
+Attention is drawn to the possibility that some of the elements of this
+document may be the subject of patent rights. CalConnect shall not be
+held responsible for identifying any or all such patent rights. Details
+of any patent rights identified during the development of the document
+will be provided in the Introduction.
+
+////
+// TODO: re-enable when we finish the IPR policy
+and/or on the CalConnect list of patent
+declarations received (see www.calconnect.com/patents).
+////
+
+Any trade name used in this document is information given for the
+convenience of users and does not constitute an endorsement.
+
+This document was prepared by Technical Committee
+_{technical-committee}_.
+

sources/unitsml-urn/sections/00-intro.adoc

@@ -0,0 +1,44 @@
+== Introduction
+
+=== General
+
+UnitsML is a comprehensive framework for representing units of measurement in
+machine-readable format. A critical aspect of this framework is the ability to
+uniquely and persistently identify units, dimensions, prefixes, quantities, and
+other related concepts.
+
+This document describes a Uniform Resource Name (URN) namespace for identifying
+UnitsML resources. The URN scheme provides a way to reference UnitsML elements
+across different systems and over time, ensuring consistent identification
+regardless of location or implementation.
+
+=== Purpose
+
+The purpose of the UnitsML URN namespace is to provide persistent,
+location-independent identifiers for UnitsML resources.
+
+This enables:
+
+* Unique identification of basic UnitsML elements such as units, dimensions,
+prefixes, quantities, unit systems, quantity kinds, and unit scales
+
+* Representation of composite expressions combining multiple elements
+
+* References to specific versions of elements
+
+* Machine-readable identifiers that can be used in various contexts, including
+XML, JSON, and plain text
+
+=== Relationship to other identification systems
+
+The UnitsML URN namespace is designed to be compatible with existing identification systems while providing a standardized approach specific to UnitsML resources.
+
+It builds upon:
+
+* RFC 8141, which defines the URN scheme
+* UnitsML entity identifiers (e.g., `u:newton` for newton)
+* Legacy NIST UnitsML entity identifiers (e.g., `NISTu11` for newton)
+
+The UnitsML URN scheme provides a bridge between these systems, allowing for
+interoperability while maintaining the specific requirements of the UnitsML
+framework.

sources/unitsml-urn/sections/01-scope.adoc

@@ -0,0 +1,16 @@
+== Scope
+
+This document specifies the syntax, semantics, and usage guidelines for the
+UnitsML URN namespace.
+
+It covers:
+
+* The basic structure of UnitsML URNs
+* Identification of fundamental UnitsML elements (units, dimensions, prefixes, quantities, unit systems, quantity kinds, types of intervals)
+* Representation of composite expressions in URN form
+* Rules for constructing and interpreting UnitsML URNs
+* Normalization algorithms for comparing equivalent expressions
+* Namespace registration information as required by RFC 8141
+
+This specification is intended to be used by developers, standards bodies, and
+organizations implementing UnitsML in their systems.

sources/unitsml-urn/sections/02-normrefs.adoc

@@ -0,0 +1,10 @@
+[bibliography]
+== Normative references
+
+* [[[unitsml-xml,UnitsML XML schema]]], https://www.unitsml.org
+
+* [[[RFC_8141,IETF RFC 8141]]], _Uniform Resource Names (URNs)_
+
+* [[[RFC_5234,IETF RFC 5234]]], _Augmented BNF for Syntax Specifications: ABNF_
+
+* UnitsML, _Units Markup Language Specification_

sources/unitsml-urn/sections/03-terms.adoc

@@ -0,0 +1,55 @@
+== Terms and definitions
+
+=== basic element
+
+fundamental component in the UnitsML framework, including unit, dimension,
+prefix, quantity, unit system, quantity kind, and unit scale
+
+=== composite expression
+
+combination of multiple basic elements using mathematical operations such as
+multiplication, division, and exponentiation
+
+=== NID
+
+namespace identifier, registered with IANA for use with URNs
+
+=== NSS
+
+namespace specific string, the portion of a URN that follows the "urn:" <NID>
+":" and conforms to the specification of the NID
+
+=== unit
+
+reference quantity with which other quantities of the same kind are compared to
+express their value
+
+=== dimension
+
+expression of the dependence of a physical quantity on the base quantities of a
+system of quantities, in the form of a product of powers of factors
+corresponding to the base quantities, omitting any numerical factors
+
+=== prefix
+
+named multiple or submultiple of a unit, used to form decimal multiples or
+submultiples of units
+
+=== quantity
+
+property of a phenomenon, body, or substance, where the property has a magnitude
+that can be expressed as a number and a reference
+
+=== unit system
+
+set of units, together with a set of equations relating them
+
+=== quantity kind
+
+aspect common to mutually comparable quantities
+
+=== unit scale
+
+specification of how values in a measurement scale are related, characterized by
+properties such as whether they are continuous or discrete, ordered,
+logarithmic, and whether they support interval or ratio comparisons

sources/unitsml-urn/sections/04-principles.adoc

@@ -0,0 +1,21 @@
+== principles
+
+The UnitsML URN scheme follows these design principles:
+
+Simplicity::
+URNs should be easy to construct, parse, and understand
+
+Readability::
+When possible, URNs should be human-readable
+
+Uniqueness::
+Each URN must uniquely identify a specific resource
+
+Persistence::
+The meaning of a URN should not change over time
+
+Compatibility::
+The scheme should be compatible with existing UnitsML identifiers
+
+Extensibility::
+The scheme should accommodate future additions to the UnitsML framework