diff --git a/Gemfile b/Gemfile
index d47c6f5..b68ee49 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,22 @@
source "https://rubygems.org"
+gem "lutaml",
+ github: "lutaml/lutaml",
+ branch: "update/xsd_support_metanorma_plugin"
+gem "lutaml-model",
+ github: "lutaml/lutaml-model",
+ branch: "main"
+gem "lutaml-xsd",
+ github: "lutaml/lutaml-xsd",
+ branch: "update/liquid_drop_methods"
+gem "metanorma"
gem "metanorma-cli"
-# gem "metanorma-nist", source: "https://rubygems.pkg.github.com/metanorma"
+gem "metanorma-plugin-lutaml",
+ github: "metanorma/metanorma-plugin-lutaml",
+ branch: "feature/unitsml_liquid_filters"
+gem "metanorma-standoc",
+ github: "metanorma/metanorma-standoc",
+ branch: "update/lutaml_xsd_preprocessor_support"
+gem "metanorma-utils",
+ github: "metanorma/metanorma-utils",
+ branch: "main"
diff --git a/sources/unitsml-xml-schema/document.adoc b/sources/unitsml-xml-schema/document.adoc
new file mode 100644
index 0000000..133f1ca
--- /dev/null
+++ b/sources/unitsml-xml-schema/document.adoc
@@ -0,0 +1,45 @@
+= CalConnect Standard: UnitsML XML schema specification
+:title: UnitsML XML schema specification
+:docnumber: 36811
+:copyright-year: 2025
+:doctype: standard
+:edition: 1
+:status: committee-draft
+:revdate: 2025-08-22
+:published-date: 2025-08-22
+:technical-committee: TC UNITS
+:fullname: Ronald Tse
+:surname: Tse
+:givenname: Ronald
+:affiliation: Ribose Inc.
+:fullname_2: Suleman Uzair
+:surname_2: Uzair
+:givenname_2: Suleman
+:affiliation_2: 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-conventions.adoc[]
+
+include::sections/05-schema.adoc[]
+
+include::sections/06-elements.adoc[]
+
+include::sections/07-complex-types.adoc[]
+
+include::sections/08-attribute-groups.adoc[]
+
+include::sections/99-bibliography.adoc[]
diff --git a/sources/unitsml-xml-schema/schemas/unitsml-v1.0-csd04.xsd b/sources/unitsml-xml-schema/schemas/unitsml-v1.0-csd04.xsd
new file mode 100644
index 0000000..23e821f
--- /dev/null
+++ b/sources/unitsml-xml-schema/schemas/unitsml-v1.0-csd04.xsd
@@ -0,0 +1,1368 @@
+
+
+
+
+
+
+
+ Container for UnitsML units, quantities, and prefixes.
+
+
+
+
+ ComplexType for the root element of an UnitsML document.
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Container for units. Use in UnitsML container or directly incorporate into a host schema.
+
+
+
+
+ Element for describing units. Use in containers UnitSet or directly incorporate into a host schema.
+
+
+
+
+ Container for describing the system of units.
+
+
+
+
+ Element containing the unit name.
+
+
+
+
+ Element containing various unit symbols. Examples include Aring (ASCII), Ã
(HTML).
+
+
+
+
+ Element for descriptive information, including version changes to the unit.
+
+
+
+
+ Element for listing the unit code value from a specific code list.
+
+
+
+
+ Container for defining derived units in terms of their root units. This allows a precise definition of a wide range of units. The goal is to improve interoperability among applications and databases which use derived units based on commonly encountered root units.
+
+
+
+
+ Element for a root unit (from an extensive enumerated list) allowing an optional prefix and power. E.g., mm^2
+
+
+
+
+ Element for those special cases where the root unit needed is not included in the enumerated list in the above element.
+
+
+
+
+ Container for providing conversion information to other units.
+
+
+
+
+ Element for providing factors for a conversion equation from another unit; stem:[y = d + ((b / c) (x + a))]
+
+
+
+
+ Element for descriptive information.
+
+
+
+
+ Element for providing unit conversion information for conversions that are more complex than the Float64ConversionFrom linear equation.
+
+
+
+
+ Element for providing conversion based on SOAP/WSDL calls to a remote server.
+
+
+
+
+ Element to describe the WSDL service.
+
+
+
+
+ Element for a description of the SpecialConversionFrom.
+
+
+
+
+ Element for all quantities that can be expressed using this unit.
+
+
+
+
+ Element to describe the definition of the unit.
+
+
+
+
+ Element to describe the historical development of the unit.
+
+
+
+
+ Element as a placeholder for additional information.
+
+
+
+
+
+ Container for items that are counted and are (in practice) combined with scientific units of measure.
+
+
+
+
+ Container for a single counted item.
+
+
+
+
+ Element containing the item name(s).
+
+
+
+
+ Element containing symbols for the item.
+
+
+
+
+ Element for descriptive information, including version changes to the item.
+
+
+
+
+ Element to describe the definition of the item.
+
+
+
+
+ Element to describe the historical development of the item.
+
+
+
+
+ Element as a placeholder for additional information.
+
+
+
+
+
+ Container for quantities.
+
+
+
+
+ Element for describing quantities and referencing corresponding units. Use in container or directly incorporate into a host schema.
+
+
+
+
+ Element containing the quantity name.
+
+
+
+
+ Element containing various quantity symbols.
+
+
+
+
+ Element for referencing a unit of measure from within the Quantity element.
+
+
+
+
+ Element for descriptive information, including version changes to the unit.
+
+
+
+
+ Element to describe the definition of the quantity.
+
+
+
+
+ Element to describe the historical development of the quantity.
+
+
+
+
+ Element as a placeholder for additional information.
+
+
+
+
+
+ Container for dimensions.
+
+
+
+
+ Element to express the dimension of a unit or quantity in terms of the SI base quantities length, mass, time, electric current, thermodynamic temperature, amount of substance, and luminous intensity.
+
+
+
+
+ Element containing the dimension of the quantity length.
+
+
+
+
+ Element containing the dimension of the quantity mass.
+
+
+
+
+ Element containing the dimension of the quantity time.
+
+
+
+
+ Element containing the dimension of the quantity electric current.
+
+
+
+
+ Element containing the dimension of the quantity thermodynamic temerature.
+
+
+
+
+ Element containing the dimension of the quantity amount of substance.
+
+
+
+
+ Element containing the dimension of the quantity luminous intensity.
+
+
+
+
+ Element containing the dimension of the quantity plane angle.
+
+
+
+
+ Element containing the dimension of any item. Note: this element is meant to be used to allow counted items to be included in the dimensioning of a derived quantity, e.g., electrons per time; usage of this element does not conform to the SI description of the dimension of a quantity in terms of seven base quantities.
+
+
+
+
+
+ Container for prefixes.
+
+
+
+
+ Element containing information about a prefix.
+
+
+
+
+ Element containing the prefix name.
+
+
+
+
+ Element containing prefix symbols.
+
+
+
+
+
+ URI indicating the unitID of the starting unit for the conversion. For units which are defined in the same document, the URI should consist of a pound sign (#) followed by the ID value.
+
+
+
+ URI indicating the unitID of the starting unit for the conversion. For units which are defined in the same document, the URI should consist of a pound sign (#) followed by the ID value.
+
+
+
+
+
+ Name of relevant publication.
+
+
+
+ Name of relevant publication.
+
+
+
+
+
+ Relevant URL for available information.
+
+
+
+ Relevant URL for available information.
+
+
+
+
+
+ An exponent of the unit, specified as powerNumerator and powerDenominator.
+
+
+
+ An integer exponent of the unit.
+
+
+
+
+ An integer value divided into the powerNumerator to create a non integer exponent of a unit. For example 1/2.
+
+
+
+
+
+ Prefix identifier; e.g., m, k, M, G. [Enumeration order is by prefix magnitude (Y to y) followed by binary prefixes.]
+
+
+
+ Prefix identifier; e.g., m, k, M, G. [Enumeration order is by prefix magnitude (Y to y) followed by binary prefixes.]
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ URL to a representation of the unit or quantity in terms of the 7 SI base dimensions.
+
+
+
+ URL to a representation of the unit or quantity in terms of the 7 SI base dimensions.
+
+
+
+
+
+
+
+ Type for the unit container.
+
+
+
+
+ Element for describing units. Use in containers UnitSet or directly incorporate into a host schema.
+
+
+
+
+
+
+ Type for the unit.
+
+
+
+
+ Container for describing the system(s) of units.
+
+
+
+
+
+
+
+ Container for defining derived units in terms of their root units. This allows a precise definition of a wide range of units. The goal is to improve interoperability among applications and databases which use derived units based on commonly encountered root units.
+
+
+
+
+
+
+ Element for descriptive information, including version changes to the unit.
+
+
+
+
+
+
+
+
+
+ Used to indicate the version of the unit output from the Units Database. Changes in the time-stamp are made if a substantive change has been made to the unit, such as a change in the unit definition or changes in conversion factors.
+
+
+
+
+ Reference to a representation of the unit or quantity in terms of the 7 SI base dimensions.
+
+
+
+
+
+ Type for the element for listing the unit code value from a specific code list.
+
+
+
+ The code associated for this unit in a specific code list.
+
+
+
+
+ The name of the code list.
+
+
+
+
+ The version of the code list containing the unit code.
+
+
+
+
+ Suggested retrieval location for this version of the code list.
+
+
+
+
+ Organization responsible for publication and/or maintenance of the code list.
+
+
+
+
+ URI for organization responsible for the code list.
+
+
+
+
+ Primary language of the element and/or its attributes. [See RFC 4646, RFC 4647 and ISO 639.]
+
+
+
+
+
+ Type for the container for defining derived units in terms of their root units. This allows a precise definition of a wide range of units. The goal is to improve interoperability among applications and databases which use derived units based on commonly encountered base units.
+
+
+
+
+ Element for a root unit (from an extensive enumerated list) allowing an optional prefix and power. E.g., mm^2
+
+
+
+
+ Element for those special cases where the root unit needed is not included in the enumerated list in the above element.
+
+
+
+
+
+
+ Type for the element for a root unit (from an extensive enumerated list) allowing an optional prefix and power. E.g., mm^2
+
+
+
+ Unit identifier; the enumerated list is basically English unit names in lowercase, with a few upper case exceptions, e.g., 32F, mmHg, pH.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Prefix identifier; e.g., m, k, M, G. [Enumeration order is by prefix magnitude (Y to y) followed by binary prefixes.]
+
+
+
+
+
+
+ Type for the element for those special cases where the root unit needed is not included in the enumerated list in the above element.
+
+
+
+ URI to identify the unit.
+
+
+
+
+ URI identifying the source and possibly the definition of the unit.
+
+
+
+
+ Optional unit annotation; e.g., a unit name if the unit identifier above is an uncommon code.
+
+
+
+
+
+
+
+
+ Type for the container for providing conversion information to other units.
+
+
+
+
+ Element for providing factors for a conversion equation from another unit; stem:[y = d + ((b / c) (x + a))]. Note: The related "conversion to" equation is a simple inversion of the above equation; i.e., stem:[x = ((c / b) (y - d)) - a].
+
+
+
+
+ Element for describing a conversion that cannot be described by the linear expression in the element Float64ConversionFrom.
+
+
+
+
+ Element for providing conversion based on SOAP/WSDL calls to a remote server.
+
+
+
+
+
+
+ Type for the element for providing factors for a conversion equation from another unit; stem:[y = d + ((b / c) (x + a))]
+
+
+
+
+
+
+
+
+ Number to be added at the start of the conversion (prior to multiplication or division) [factor 'a' in equation].
+
+
+
+
+ Indicates the position of the least
+significant digit (in decimal) of
+the initialAddend; the position of
+this digit is given by ten to
+additive inverse of this number.
+
+
+
+
+ Number by which to multiply sum of initial addend and initial value [factor 'b' in equation].
+
+
+
+
+ Number of significant digits in the multiplicand value.
+
+
+
+
+ Divisor to be applied to the value at the same time as the multiplicand [factor 'c' in equation].
+
+
+
+
+ Number of significant digits in the divisor value.
+
+
+
+
+ Number to be added at the end of the conversion [factor 'd' in equation].
+
+
+
+
+ Indicates the position of the least
+significant digit (in decimal) of
+the finalAddend; the position of
+this digit is given by ten to
+additive inverse of this number.
+
+
+
+
+ Indicates if the conversion is exact.
+
+
+
+
+
+ Type for the element for providing unit conversion information for conversions that are more complex than the Float64ConversionFrom linear equation.
+
+
+
+
+ Description of the conversion.
+
+
+
+
+
+
+ URL for external description of the conversion or for an online convertor.
+
+
+
+
+
+
+ Type for the element for providing unit conversion information for conversions that are more complex than the Float64ConversionFrom linear equation.
+
+
+
+
+ Description of the service.
+
+
+
+
+
+
+
+ URL for external WSDL definition file.
+
+
+
+
+
+
+ Type for a set of counted items.
+
+
+
+
+
+
+
+ Type for a single counted item.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Type for quantity container.
+
+
+
+
+
+
+
+ Type for the quantity.
+
+
+
+
+
+ Element containing various quantity symbols.
+
+
+
+
+ Element for specifying particular units associated with the quantity.
+
+
+
+
+ Element for descriptive information, including version changes to the quantity.
+
+
+
+
+
+
+
+
+
+ Type of the quantity. For example base or derived.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Type for the dimension container.
+
+
+
+
+ Element to express a unit or quantity in terms of the SI base quantities length, mass, time, electric current, thermodynamic temperature, amount of substance, and luminous intensity.
+
+
+
+
+
+
+ Type for dimension.
+
+
+
+ This unbounded sequence allows any order of any number of elements; e.g., L^1 · L^-1.
+
+
+
+
+
+
+
+
+
+
+
+ Element containing the dimension of any item. Note: this element is meant to be used to allow counted items to be included in the dimensioning of a derived quantity, e.g., electrons per time; usage of this element does not conform to the SI description of the dimension of a quantity in terms of seven base quantities.
+
+
+
+
+
+
+ Boolean to designate that a quantity or unit is dimensionless.
+
+
+
+
+
+ Type of the quantity length.
+
+
+
+ Symbol of the quantity length.
+
+
+
+
+
+
+ Type of the quantity mass.
+
+
+
+ Symbol of the quantity mass.
+
+
+
+
+
+
+ Type of the quantity time.
+
+
+
+ Symbol of the quantity time.
+
+
+
+
+
+
+ Type of the quantity electric current.
+
+
+
+ Symbol of the quantity electric current.
+
+
+
+
+
+
+ Type of the quantity thermodynamic temperature.
+
+
+
+ Symbol of the quantity thermodynamic temperature.
+
+
+
+
+
+
+ Type of the quantity amount of substance.
+
+
+
+ Symbol of the quantity amount of substance.
+
+
+
+
+
+
+ Type of the quantity luminous intensity.
+
+
+
+ Symbol of the quantity luminous intensity.
+
+
+
+
+
+
+ Type of the quantity plane angle.
+
+
+
+ Symbol of the quantity plane angle.
+
+
+
+
+
+
+ Type of the quantity represented by a counted item, e.g., electron
+
+
+
+ Unique URL for identifying or describing the item.
+
+
+
+
+ Symbol for the item.
+
+
+
+
+
+
+
+ Type for container for prefixes.
+
+
+
+
+
+
+
+ Type for element for describing prefixes. Use in container PrefixSet.
+
+
+
+
+
+
+
+
+ The base of the prefix system, i.e., 10 (SI) or 2 (binary).
+
+
+
+
+
+
+
+
+
+
+ The exponential power of the prefix with relation to the base.
+
+
+
+
+
+
+ Type for name. Used for names in units, quantities, and prefixes.
+
+
+
+
+
+
+
+
+
+ Type for unit system.
+
+
+
+ Name of the unit system. For example, SI, inch-pound, CGS, and MKS.
+
+
+
+
+ Description of the unit relative to the unit system. Examples are SI_base and non-SI_not_acceptable.
+
+
+
+
+
+
+ Type for symbols. Used in units, quantities, and prefixes.
+
+
+
+
+
+
+
+ Type of symbol representation. Examples include ASCII, unicode, HTML, and MathML.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Type for notes. Used in units and conversion factors.
+
+
+
+
+
+
+
+
+
+ Type for definition.
+
+
+
+
+
+
+
+
+
+
+
+ Type for history.
+
+
+
+
+
+
+
+
+
+
+
+ Type for remark.
+
+
+
+
+
+
+
+ Primary language of the element and/or its attributes. [See RFC 4646, RFC 4647 and ISO 639.]
+
+
+
+
+
+
+
+ Type for reference to a unit or quantity.
+
+
+
+ URL to the reference item.
+
+
+
+
+ Name of the referenced item.
+
+
+
+
+ Primary language of the element and/or its attributes. [See RFC 4646, RFC 4647 and ISO 639.]
+
+
+
+
diff --git a/sources/unitsml-xml-schema/sections/00-foreword.adoc b/sources/unitsml-xml-schema/sections/00-foreword.adoc
new file mode 100644
index 0000000..b0c4217
--- /dev/null
+++ b/sources/unitsml-xml-schema/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}_.
+
diff --git a/sources/unitsml-xml-schema/sections/00-intro.adoc b/sources/unitsml-xml-schema/sections/00-intro.adoc
new file mode 100644
index 0000000..c4b051a
--- /dev/null
+++ b/sources/unitsml-xml-schema/sections/00-intro.adoc
@@ -0,0 +1,9 @@
+== Introduction
+
+The UnitsML XML Schema defines the structure and content of the
+representation of UnitsML objects in XML.
+
+It is defined as an XML Schema definition (XSD) for use in XML
+applications. The schema is intended to be used in conjunction with the
+UnitsML specification, which defines the semantics of the UnitsML
+vocabulary.
diff --git a/sources/unitsml-xml-schema/sections/01-scope.adoc b/sources/unitsml-xml-schema/sections/01-scope.adoc
new file mode 100644
index 0000000..9850c5e
--- /dev/null
+++ b/sources/unitsml-xml-schema/sections/01-scope.adoc
@@ -0,0 +1,4 @@
+== Scope
+
+This document describes the UnitsML XML Schema (UnitsML XSD), which is an
+XML Schema definition for the representation of UnitsML objects in XML.
diff --git a/sources/unitsml-xml-schema/sections/02-normrefs.adoc b/sources/unitsml-xml-schema/sections/02-normrefs.adoc
new file mode 100644
index 0000000..f53842b
--- /dev/null
+++ b/sources/unitsml-xml-schema/sections/02-normrefs.adoc
@@ -0,0 +1,6 @@
+[bibliography]
+== Normative references
+
+* [[[w3c_xmlschema,W3C xmlschema-1]]]
+* [[[w3c_xmlschema-1,W3C xmlschema11-1]]]
+* [[[w3c_xmlschema-2,W3C xmlschema11-2]]]
diff --git a/sources/unitsml-xml-schema/sections/03-terms.adoc b/sources/unitsml-xml-schema/sections/03-terms.adoc
new file mode 100644
index 0000000..05c991f
--- /dev/null
+++ b/sources/unitsml-xml-schema/sections/03-terms.adoc
@@ -0,0 +1,48 @@
+== Terms and definitions
+
+=== unit
+
+standard quantity used to express a physical quantity
+
+=== basic unit
+
+unit not derived from other units
+
+=== composite unit
+
+unit derived from two or more basic units conjoined by multiplication or division
+
+=== prefix
+
+modifier to a unit with a fixed factor
+
+=== quantity
+
+type of measurement that is represented by a unit
+
+[example]
+distance, moment of force, temperature, energy.
+
+=== dimension
+
+basic physical quantity that can be expressed in terms of fundamental
+quantities
+
+[example]
+length, mass, time, plane angle.
+
+=== unit name
+
+name of a unit
+
+=== unit symbol
+
+abbreviated representation of a unit
+
+=== unit reference
+
+reference identifier to a unit in a database
+
+=== unit dimensions
+
+fundamental quantities to which the unit applies
diff --git a/sources/unitsml-xml-schema/sections/04-conventions.adoc b/sources/unitsml-xml-schema/sections/04-conventions.adoc
new file mode 100644
index 0000000..5cfa8b5
--- /dev/null
+++ b/sources/unitsml-xml-schema/sections/04-conventions.adoc
@@ -0,0 +1,90 @@
+== Conventions
+
+=== General
+
+Elements and attributes defined in the UnitsML XML schema are described in
+following clauses.
+
+Each element and attribute is described in a separate entry, with entries
+arranged in alphabetical order.
+
+=== Element
+
+Each element entry contains the following information:
+
+* The XML Name (tag or generic identifier) of the element or attribute that is
+used in UnitsML XML files.
++
+[example]
+====
+``
+====
+
+* The informational name of the element or attribute.
++
+[example]
+====
+Unit
+====
+
+* A description of the element or attribute.
++
+[example]
+====
+For the element ``: "Specifies a unit of measurement."
+====
+
+* A list of all of the attributes that may be applied to the element, with first
+the attribute name and then the attribute's informal expanded name. Attribute
+names are prefixed with an at sign (`@`).
+
+* The content model or type of the element's content. If the element has a type,
+the type is given first, with a link to the type definition. If the element
+does not have a type, the content model is described in detail, supporting
+groups, sequences, choices, one of and any of.
++
+[example]
+====
+string, integer, boolean, or a reference to a simple or complex type defined in
+the schema.
+====
+
+
+=== Attribute
+
+Each attribute entry contains the following information:
+
+* The XML Name of the attribute.
++
+[example]
+====
+`@quantityType`
+====
+
+* The informational name of the attribute.
++
+[example]
+====
+Quantity Type
+====
+
+* A description of the attribute
+[example]
+====
+Type of the quantity.
+====
+
+* The data type of the attribute's value.
++
+[example]
+====
+string, integer, boolean, or a reference to a simple type defined in the schema.
+====
+
+* A list of all of the elements or groups of elements in which the attribute may
+be used, with first the element name and then the element's informal
+expanded name. Element names are not prefixed.
+
+* For each element or group of elements in which the attribute may be used, a
+block of usage information with required or suggested values and other
+information.
diff --git a/sources/unitsml-xml-schema/sections/05-schema.adoc b/sources/unitsml-xml-schema/sections/05-schema.adoc
new file mode 100644
index 0000000..0281ec0
--- /dev/null
+++ b/sources/unitsml-xml-schema/sections/05-schema.adoc
@@ -0,0 +1,26 @@
+== Schema
+
+The UnitsML XML schema is defined in the file `unitsml.xsd`, which is
+included in the UnitsML distribution.
+
+The root element of the schema is ``, which contains all other
+elements.
+
+The schema is defined using the W3C XML Schema Definition Language
+(<>), and conforms to <> and
+<>.
+
+The UnitsML XML schema may be used in the following ways:
+
+* To validate UnitsML XML documents, ensuring that they conform to the
+ structure and content rules defined in the schema.
+
+* To incorportate UnitsML XML into XML application schemas, allowing for the
+ integration of UnitsML data with other XML-based data formats.
+
+* To generate code or data structures in programming languages that
+ support XML schema, facilitating the processing of UnitsML XML
+ documents.
+
+The UnitsML XML schema is maintained by the CalConnect TC UNITS Technical
+Committee, and is available from https://www.unitsml.org.
diff --git a/sources/unitsml-xml-schema/sections/06-elements.adoc b/sources/unitsml-xml-schema/sections/06-elements.adoc
new file mode 100644
index 0000000..a563486
--- /dev/null
+++ b/sources/unitsml-xml-schema/sections/06-elements.adoc
@@ -0,0 +1,9 @@
+== Elements
+
+[lutaml_xsd,schemas/unitsml-v1.0-csd04.xsd,schema,skip_rendering_of=annotation,include_path=templates]
+----
+{% for item in schema.elements_sorted_by_name %}
+include::../templates/_element.adoc[]
+
+{% endfor %}
+----
diff --git a/sources/unitsml-xml-schema/sections/07-complex-types.adoc b/sources/unitsml-xml-schema/sections/07-complex-types.adoc
new file mode 100644
index 0000000..81feb11
--- /dev/null
+++ b/sources/unitsml-xml-schema/sections/07-complex-types.adoc
@@ -0,0 +1,9 @@
+== Complex types
+
+[lutaml_xsd,schemas/unitsml-v1.0-csd04.xsd,schema,skip_rendering_of=annotation,include_path=templates]
+----
+{% for item in schema.complex_types_sorted_by_name %}
+include::../templates/_complex_type.adoc[]
+
+{% endfor %}
+----
diff --git a/sources/unitsml-xml-schema/sections/08-attribute-groups.adoc b/sources/unitsml-xml-schema/sections/08-attribute-groups.adoc
new file mode 100644
index 0000000..8c1e2a6
--- /dev/null
+++ b/sources/unitsml-xml-schema/sections/08-attribute-groups.adoc
@@ -0,0 +1,9 @@
+== Attribute groups
+
+[lutaml_xsd,schemas/unitsml-v1.0-csd04.xsd,schema,skip_rendering_of=annotation,include_path=templates]
+----
+{% for item in schema.attribute_groups_sorted_by_name %}
+include::../templates/_attribute_group.adoc[]
+
+{% endfor %}
+----
diff --git a/sources/unitsml-xml-schema/sections/99-bibliography.adoc b/sources/unitsml-xml-schema/sections/99-bibliography.adoc
new file mode 100644
index 0000000..f494396
--- /dev/null
+++ b/sources/unitsml-xml-schema/sections/99-bibliography.adoc
@@ -0,0 +1,2 @@
+[bibliography]
+== Bibliography
diff --git a/sources/unitsml-xml-schema/templates/_attribute_group.adoc b/sources/unitsml-xml-schema/templates/_attribute_group.adoc
new file mode 100644
index 0000000..99a0691
--- /dev/null
+++ b/sources/unitsml-xml-schema/templates/_attribute_group.adoc
@@ -0,0 +1,72 @@
+{%# Documentation #%}
+
+{%liquid
+ assign item_attributes = item.attribute_elements
+ assign used_by_items = item.used_by
+%}
+{% capture docs %}
+{% for paragraph in item.annotation.documentation %}
+{{ paragraph.content }}
+
+{% endfor %}
+{% endcapture %}
+
+[[xsd_{{item.name}}]]
+=== `{{ item.name }}`
+
+==== Group
+
+{{ docs }}
+
+{% if used_by_items.size > 0 %}
+This attribute group is used by:
+
+{% for used_by in used_by_items %}
+{% capture description %}
+{% for paragraph in used_by.annotation.documentation %}
+{{ paragraph.content }}
+
+{% endfor %}
+{% endcapture %}
+@{{ used_by.name }}::
+{% if description %}
++
+--
+{{ description }}
+--
+{% endif %}
+
+{% endfor %}
+{% endif %}
+
+==== Attributes
+
+{% if item_attributes.size > 0 %}
+{% for attribute in item_attributes %}
+{% capture attribute_docs %}
+{% for paragraph in attribute.annotation.documentation %}
+{{ paragraph.content }}
+
+{% endfor %}
+{% endcapture %}
+`@{{ attribute.name | default: attribute.ref }}`:: {% if attribute.referenced_type %}`{{ attribute.referenced_type }}`{% endif %} `[{{ attribute.cardinality }}]`
+{% if attribute_docs %}
++
+--
+{{ attribute_docs }}
+--
+{% endif %}
+
+{% endfor %}
+{% else %}
+No attributes defined.
+{% endif %}
+
+{%- capture xmlns -%}xmlns="http://www.w3.org/2001/XMLSchema" {% endcapture %}
+
+.XSD source of `<{{ item.name }}>`
+
+[source,xml]
+-----
+{{ item | to_xml_representation: skip_rendering_of | remove: xmlns }}
+-----
diff --git a/sources/unitsml-xml-schema/templates/_child_elements.adoc b/sources/unitsml-xml-schema/templates/_child_elements.adoc
new file mode 100644
index 0000000..e46ee65
--- /dev/null
+++ b/sources/unitsml-xml-schema/templates/_child_elements.adoc
@@ -0,0 +1,20 @@
+{%- capture cardinality -%}{{ child.min_occurrences }}..{{ child.max_occurrences }}{%- endcapture -%}
+{%- if child.sequence? -%}
+{%- assign min_or_max_ocurrs = child.min_occurs | default: child.max_occurs -%}
+{%- if min_or_max_ocurrs -%}{%- assign indent = " " %}
+ Start Sequence [{{ cardinality }}]
+{%- endif -%}{%- for element in child.resolved_element_order %}{%- if element.annotation? or element.attribute? or element.attribute_group? -%}{%- continue -%}{%- else %}
+ {{ indent }}{% render "child_elements", child: element -%}
+{%- endif -%}
+{%- endfor %}
+{%- if min_or_max_ocurrs %}
+ End Sequence
+{%- endif -%}
+{%- elsif child.any? -%}
+ Allow any elements from any namespace ({{ child.process_contents }} validation). [{{ cardinality }}]
+{%- elsif child.simple_content? %}
+ {{ child.base_type }}
+{%- else -%}
+{%- assign element_name = child.ref | default: child.name -%}
+ <{{ element_name }}> ... [{{ cardinality }}]
+{%- endif -%}
\ No newline at end of file
diff --git a/sources/unitsml-xml-schema/templates/_complex_type.adoc b/sources/unitsml-xml-schema/templates/_complex_type.adoc
new file mode 100644
index 0000000..01dd6ad
--- /dev/null
+++ b/sources/unitsml-xml-schema/templates/_complex_type.adoc
@@ -0,0 +1,139 @@
+{%# Documentation #%}
+{%liquid
+ assign item_attributes = item.attribute_elements
+ assign item_children = item.child_elements
+ assign used_by_items = item.used_by
+ assign item_element_order = item.resolved_element_order
+ assign elements = item.direct_child_elements
+%}
+{% capture docs %}
+{% for paragraph in item.annotation.documentation %}
+{{ paragraph.content }}
+
+{% endfor %}
+{% endcapture %}
+
+[[xsd_{{item.name}}]]
+=== `{{ item.name }}`
+
+==== General
+
+{{ docs }}
+
+{% if used_by_items.size > 0 %}
+This complex type is used by:
+
+{% for used_by in used_by_items %}
+* {{ used_by.name }} (<>)
+
+{% endfor %}
+{% endif %}
+
+==== Attributes
+
+{% if item_attributes.size > 0 %}
+{% for attribute in item_attributes %}
+{% capture attribute_docs %}
+{% for paragraph in attribute.annotation.documentation %}
+{{ paragraph.content }}
+
+{% endfor %}
+{% endcapture %}
+
+`@{{ attribute.ref | default: attribute.name }}`:: {% if attribute.referenced_type %}`{{ attribute.referenced_type }}`{% endif %} `[{{ attribute.cardinality }}]`
+{% if attribute_docs %}
++
+--
+{{ attribute_docs }}
+--
+{% endif %}
+
+{% endfor %}
+{% else %}
+No attributes defined.
+{% endif %}
+
+==== Content model
+
+{% comment %}
+TODO: The "content model" section needs to describe sequence, anyOf, allOf,
+choice, etc, in proper hierarchy.
+{% endcomment %}
+
+{% if item_children.size > 0 %}
+
+{% for child in item_children %}
+{% assign item_name = child.ref || child.name %}
+{% if item_name %}
+{% capture child_docs %}
+{% for paragraph in child.annotation.documentation %}
+{{ paragraph.content }}
+
+{% endfor %}
+{% endcapture %}
+
+{{ item_name }}:: {% if child.referenced_type %}`{{ child.referenced_type }}`{% endif %} [{{ child.min_occurrences }}..{{ child.max_occurrences }}]
+{% if child_docs %}
++
+--
+{{ child_docs }}
+--
+{% endif %}
+
+{% else %}
+{{ child }}
+
+{% endif %}
+{% endfor %}
+{% else %}
+No child elements defined.
+{% endif %}
+
+
+
+[example]
+.Illustrative usage of `<{{ item.name }}>`
+====
+[source,xml]
+-----
+<...{% for attr in item_attributes %}
+{%- capture type %}
+{%- if attr.referenced_type %}
+{{- attr.referenced_type }}
+{%- elsif attr.simple_type.restriction %}
+{{- attr.simple_type.restriction.base }} (value comes from list: '{{ attr.simple_type.restriction.enumeration | map: "value" | join: "'|'" }}')
+{%- elsif attr.simple_type.union %}
+{%- assign union = attr.simple_type.union -%}
+{% capture enums %}
+{%- for u_s_type in union.simple_type -%}
+[ {{ u_s_type.restriction.base }} (value comes from list: {{- u_s_type.restriction.enumeration | map: "value" | join: "'|'" -}}) ]
+{%- endfor -%}
+{% endcapture -%}
+union of: [ {{ union.member_types }}, {{ enums }} ]
+{%- endif %}
+{%- endcapture %}
+ {{ attr.referenced_name }}="{{ attr.fixed | default: type }}" [{{ attr.cardinality }}]
+{%- endfor -%}
+{%- if elements.size > 0 -%}
+{% if item_attributes.size > 0 %}
+>
+{%- else -%}>{% endif %}
+{%- if item.mixed %}
+
+{%- endif -%}{%- for child in elements -%}{%- if child.annotation? or child.attribute? or child.attribute_group? -%}{%- continue -%}{%- else -%}
+{% render "child_elements", child: child -%}
+{% endif -%}
+{% endfor %}
+
+{%- else %}
+/>
+{% endif %}
+-----
+====
+{%- capture xmlns -%}xmlns="http://www.w3.org/2001/XMLSchema" {% endcapture %}
+
+.XSD source of `<{{ item.name }}>`
+[source,xml]
+-----
+{{ item | to_xml_representation: skip_rendering_of | remove: xmlns }}
+-----
diff --git a/sources/unitsml-xml-schema/templates/_element.adoc b/sources/unitsml-xml-schema/templates/_element.adoc
new file mode 100644
index 0000000..7478905
--- /dev/null
+++ b/sources/unitsml-xml-schema/templates/_element.adoc
@@ -0,0 +1,136 @@
+{%# Documentation #%}
+{%liquid
+ assign item_complex_type = item.referenced_complex_type
+ assign item_attributes = item.attributes
+ assign item_children = item.child_elements
+ assign used_by_items = item.used_by
+ assign elements = item_complex_type.direct_child_elements
+%}
+{% capture docs %}
+{% for paragraph in item.annotation.documentation %}
+{{ paragraph.content }}
+
+{% endfor %}
+{% endcapture %}
+
+[[xsd_{{item.name}}]]
+=== `<{{ item.name }}>`
+
+==== General
+
+{{ docs }}
+
+{% if used_by_items.size > 0 %}
+This element is used by:
+
+{% for used_by in used_by_items %}
+* {{ used_by.name }} (<>)
+
+{% endfor %}
+{% endif %}
+
+==== Attributes
+
+{% if item_attributes.size > 0 %}
+{% for attribute in item_attributes %}
+{% capture attribute_docs %}
+{% for paragraph in attribute.annotation.documentation %}
+{{ paragraph.content }}
+
+{% endfor %}
+{% endcapture %}
+`@{{ attribute.name | default: attribute.ref }}`:: {% if attribute.referenced_type %}`{{ attribute.referenced_type }}`{% endif %} `[{{ attribute.cardinality }}]`
+{% if attribute_docs %}
++
+--
+{{ attribute_docs }}
+--
+{% endif %}
+
+{% endfor %}
+{% else %}
+No attributes defined.
+{% endif %}
+
+==== Content model
+
+This element is specified the type {{ item.type }} (<>).
+
+{% if item_children.size > 0 %}
+
+{% for child in item_children %}
+{% assign item_name = child.ref | default: child.name %}
+{% if item_name %}
+{% capture child_docs %}
+{% for paragraph in child.annotation.documentation %}
+{{ paragraph.content }}
+
+{% endfor %}
+{% endcapture %}
+
+{{ item_name }}:: {% if child.referenced_type %}`{{ child.referenced_type }}`{% endif %} [{{ child.min_occurrences }}..{{ child.max_occurrences }}]
+{% if child_docs %}
++
+--
+{{ child_docs }}
+--
+{% endif %}
+
+{% else %}
+{{ child }}
+
+{% endif %}
+{% endfor %}
+
+{% else %}
+No child elements defined.
+{% endif %}
+
+
+[example]
+.Illustrative usage of `<{{ item.name }}>`
+====
+[source,xml]
+-----
+<{{item.name}}{% for attr in item_attributes %}
+{%- capture type %}
+{%- if attr.referenced_type %}
+{{- attr.referenced_type }}
+{%- elsif attr.simple_type.restriction -%}
+{{- attr.simple_type.restriction.base -}} (value comes from list: '{{ attr.simple_type.restriction.enumeration | map: "value" | join: "'|'" }}')
+{%- elsif attr.simple_type.union -%}
+{%- assign union = attr.simple_type.union -%}
+{% capture enums %}
+{%- for u_s_type in union.simple_type -%}
+{% assign something = u_s_type.restriction %}
+{{- u_s_type.restriction.enumeration | map: "value" | join: "'|'" -}}
+{%- endfor -%}
+{% endcapture %}
+{{- union.member_types }} (value comes from list: {{ enums }})
+{%- endif %}
+{%- endcapture %}
+ {{ attr.referenced_name }}="{{ attr.fixed | default: type }}" [{{ attr.cardinality }}]
+{%- endfor -%}
+{%- if elements.size > 0 -%}
+{% if item_attributes.size > 1 %}
+>
+{%- else -%}>{% endif %}
+{%- if item_complex_type.mixed %}
+
+{%- endif -%}{%- for child in elements -%}{%- if child.annotation? or child.attribute? or child.attribute_group? -%}{%- continue -%}{%- else -%}
+{% render "child_elements", child: child -%}
+{% endif -%}
+{% endfor %}
+
+{%- else %}
+/>
+{% endif %}
+-----
+====
+{%- capture xmlns -%}xmlns="http://www.w3.org/2001/XMLSchema" {% endcapture %}
+
+.XSD source of `<{{ item.name }}>`
+[source,xml]
+-----
+{{ item | to_xml_representation: skip_rendering_of | remove: xmlns }}
+-----