diff --git a/AGENTS.md b/AGENTS.md
new file mode 100644
index 0000000..7a1a68a
--- /dev/null
+++ b/AGENTS.md
@@ -0,0 +1,46 @@
+# Repository Guidelines
+
+## Project Structure & Module Organization
+
+`longitude-one/spatial-core` provides shared PHP primitives for LongitudeOne spatial libraries.
+PSR-4 maps `LongitudeOne\Core\` to `lib/`, which contains `Enum/`, `Exception/`, and `Diagnostic/`.
+Tests live in `tests/Unit/` and `tests/Contract/` under `LongitudeOne\Core\Tests\`.
+Quality configurations and isolated tool dependencies live in `quality/`; CI lives in `.github/workflows/`.
+Consult `README.md` for public behavior and `CONTRIBUTING.md` for the full contribution checklist.
+
+## Build, Test, and Development Commands
+
+Use PHP 8.3+ with `mbstring` and Composer. This library has no application server or asset build.
+
+- `composer install`: install library development dependencies.
+- `composer upgrade-tools`: install or update project and quality-tool dependencies; inspect resulting changes.
+- `composer validate --strict`: validate package metadata.
+- `composer test`: run PHPUnit.
+- `composer test-coverage`: generate coverage reports under `.phpunit.cache/`; requires a coverage driver.
+- `composer quality`: run PHP-CS-Fixer checks, PHPStan level 9, PHPMD, and PHP_CodeSniffer.
+- `composer quality-fix`: apply PHP-CS-Fixer formatting; rerun quality checks afterward.
+- `composer markdownlint`: lint Markdown; install Node.js and `markdownlint-cli2` first.
+- `git diff --check`: detect whitespace errors before committing.
+
+## Coding Style & Naming Conventions
+
+Use four-space indentation, LF endings, strict types, explicit types, and the existing copyright header.
+Follow the configured Symfony/PHP-CS-Fixer and PSR-2-based rules.
+Use PascalCase class names, camelCase methods and variables, and uppercase enum cases.
+Match filenames to symbols, such as `GeometryTypeEnum.php`; preserve established enum backing values.
+
+## Testing Guidelines
+
+Use PHPUnit 12.5 with `*Test.php` classes and descriptive `test...` methods.
+Mirror source organization in unit tests; place public-contract checks in `tests/Contract/`.
+Run focused tests with `composer test -- --filter GeometryTypeEnumTest`.
+Cover boundary cases, exceptions, and regressions. When extending an enum, verify every method for the added cases.
+Generate coverage for executable changes; no numeric coverage minimum is configured in PHPUnit.
+
+## Commit & Pull Request Guidelines
+
+Follow Conventional Commits, as in history: `feat: ...`, `fix: ...`, or `chore: ...`.
+Use optional scopes, for example `fix(range): report the correct axis error`.
+Link the issue, explain behavioral changes, and report validation results in the PR.
+All required checks must pass before pushing. Obtain independent review and Alexandre’s merge decision.
+Do not mark work Done before merge. Escalate unresolved public API, compatibility, architecture, or normative decisions to Alexandre.
diff --git a/CHANGELOG.md b/CHANGELOG.md
index aa380cb..740a14c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,7 +17,7 @@ All notable changes to this project will be documented in this file. See [commit
 
 ### ✨ New Features
 
-* Implement DiagnosticValueFormatter ([#4](https://github.com/longitude-one/spatial-core/issues/4)) ([db6f205](https://github.com/longitude-one/spatial-core/commit/db6f205768ace5ae3c9bbc1a3736f4926681799b)), closes [#3](https://github.com/longitude-one/spatial-core/issues/3)
+* Implement DiagnosticValueFormatter ([#4](https://github.com/longitude-one/spatial-core/issues/4)) ([db6f205](https://github.com/longitude-one/spatial-core/commit/db6f205768ace5ae3c9bbc1a3736f4926681799b))
 
 ### 🔧 Maintenance
 
diff --git a/README.md b/README.md
index 8168dec..e001270 100644
--- a/README.md
+++ b/README.md
@@ -149,13 +149,20 @@ assert(!$dimension->isCurve());
 
 ### `GeometryTypeEnum`
 
-`GeometryTypeEnum` names the concrete shape of a spatial value, such as a point, line string, polygon,
-or geometry collection. It exposes a type's homogeneous component and topological dimension, making
-it useful for creating and validating multipart geometries. Its `isInstantiable()` method returns
-`false` for the abstract `SURFACE` type and `true` for every other enum case, including `MULTICURVE`
-and `MULTISURFACE`. The classification considers OGC Simple Feature Access 1.2.1 sections 6.1.2,
-6.1.10, and 6.1.13, and ISO/IEC CD 13249-3:201x(E) sections 4.2, 4.2.8, 4.2.16, and 4.2.18; the ISO
-source is a Committee Draft, not a published ISO edition.
+`GeometryTypeEnum` identifies geometry types and exposes their homogeneous component and topological
+dimension. Its `isInstantiable()` method returns `false` for `GEOMETRY`, `CURVE`, `SOLID`, and `SURFACE`,
+and `true` for every other case, including `MULTICURVE` and `MULTISURFACE`.
+
+The additional types `BREPSOLID`, `CIRCLE`, `CLOTHOID`, `COMPOUNDSURFACE`, `ELLIPTICALCURVE`,
+`GEODESICSTRING`, `NURBSCURVE`, and `SPIRALCURVE` are instantiable. `BREPSOLID` has volume dimension,
+`COMPOUNDSURFACE` has surface dimension, and the remaining types have curve dimension. None is a
+multi-geometry or a geometry collection. `CIRCLE` and `GEODESICSTRING` have `POINT` components.
+The other additions have no single concrete component type exposed by this enum: compound surfaces
+and solid shells can use different surface subtypes, while NURBS curves use weighted control points
+and knots, and the other curves use constructive parameters.
+
+These additions follow ISO/IEC DIS 13249-3, fifth-edition ballot text N2593 dated 2015-01-25,
+clauses 4.2.7–4.2.12, 4.2.20, 4.2.22, 7.4.1–7.9.1, 8.7.1, and 9.2.1. Enum membership does not imply concrete geometry classes or support for encoding or decoding these types.
 
 ```php
 use LongitudeOne\Core\Enum\GeometryTypeEnum;
diff --git a/lib/Enum/GeometryTypeEnum.php b/lib/Enum/GeometryTypeEnum.php
index 63ba88c..99eb109 100644
--- a/lib/Enum/GeometryTypeEnum.php
+++ b/lib/Enum/GeometryTypeEnum.php
@@ -18,18 +18,36 @@
  */
 enum GeometryTypeEnum: string
 {
+    /** A solid bounded by exterior and interior surface shells. */
+    case BREPSOLID = 'BRepSolid';
+
+    /** A simple closed circular curve. */
+    case CIRCLE = 'Circle';
+
     /** A route formed from circular arcs. */
     case CIRCULARSTRING = 'CircularString';
 
+    /** A curve with clothoid interpolation. */
+    case CLOTHOID = 'Clothoid';
+
     /** A route made of linear and circular segments. */
     case COMPOUNDCURVE = 'CompoundCurve';
 
+    /** A surface formed from connected surface patches. */
+    case COMPOUNDSURFACE = 'CompoundSurface';
+
     /** An abstract curve geometry type. */
     case CURVE = 'Curve';
 
     /** An area bounded by curves. */
     case CURVEPOLYGON = 'CurvePolygon';
 
+    /** A curve with elliptical interpolation. */
+    case ELLIPTICALCURVE = 'EllipticalCurve';
+
+    /** A route formed from geodesic segments. */
+    case GEODESICSTRING = 'GeodesicString';
+
     /** The generic geometry type. */
     case GEOMETRY = 'Geometry';
 
@@ -54,6 +72,9 @@ enum GeometryTypeEnum: string
     /** A collection of surfaces. */
     case MULTISURFACE = 'MultiSurface';
 
+    /** A non-uniform rational B-spline curve. */
+    case NURBSCURVE = 'NURBSCurve';
+
     /** A location. */
     case POINT = 'Point';
 
@@ -66,6 +87,9 @@ enum GeometryTypeEnum: string
     /** A solid geometry type. */
     case SOLID = 'Solid';
 
+    /** A curve with spiral interpolation. */
+    case SPIRALCURVE = 'SpiralCurve';
+
     /** An abstract surface geometry type. */
     case SURFACE = 'Surface';
 
@@ -81,7 +105,7 @@ enum GeometryTypeEnum: string
     public function componentType(): ?self
     {
         return match ($this) {
-            self::CIRCULARSTRING, self::LINESTRING, self::MULTIPOINT => self::POINT,
+            self::CIRCLE, self::CIRCULARSTRING, self::GEODESICSTRING, self::LINESTRING, self::MULTIPOINT => self::POINT,
             self::POLYGON, self::MULTILINESTRING, self::TRIANGLE => self::LINESTRING,
             self::MULTIPOLYGON, self::POLYHEDRALSURFACE => self::POLYGON,
             self::TIN => self::TRIANGLE,
@@ -135,12 +159,19 @@ public function topologicalDimension(): ?TopologicalDimensionEnum
     {
         return match ($this) {
             self::POINT, self::MULTIPOINT => TopologicalDimensionEnum::POINT,
+            self::CIRCLE,
             self::CIRCULARSTRING,
+            self::CLOTHOID,
             self::COMPOUNDCURVE,
             self::CURVE,
+            self::ELLIPTICALCURVE,
+            self::GEODESICSTRING,
             self::LINESTRING,
             self::MULTICURVE,
-            self::MULTILINESTRING => TopologicalDimensionEnum::CURVE,
+            self::MULTILINESTRING,
+            self::NURBSCURVE,
+            self::SPIRALCURVE => TopologicalDimensionEnum::CURVE,
+            self::COMPOUNDSURFACE,
             self::CURVEPOLYGON,
             self::MULTIPOLYGON,
             self::MULTISURFACE,
@@ -149,7 +180,7 @@ public function topologicalDimension(): ?TopologicalDimensionEnum
             self::SURFACE,
             self::TIN,
             self::TRIANGLE => TopologicalDimensionEnum::SURFACE,
-            self::SOLID => TopologicalDimensionEnum::VOLUME,
+            self::BREPSOLID, self::SOLID => TopologicalDimensionEnum::VOLUME,
             default => null,
         };
     }
diff --git a/quality/markdownlint/.markdownlint-cli2.json b/quality/markdownlint/.markdownlint-cli2.json
index 9be23e6..5b42e27 100644
--- a/quality/markdownlint/.markdownlint-cli2.json
+++ b/quality/markdownlint/.markdownlint-cli2.json
@@ -2,7 +2,8 @@
     "config": {
         "MD013": {
             "line_length": 200
-        }
+        },
+        "MD024": false
     },
     "globs": [
         "**/*.md"
diff --git a/tests/Unit/Enum/GeometryTypeEnumTest.php b/tests/Unit/Enum/GeometryTypeEnumTest.php
index 7b4808f..c675d05 100644
--- a/tests/Unit/Enum/GeometryTypeEnumTest.php
+++ b/tests/Unit/Enum/GeometryTypeEnumTest.php
@@ -26,6 +26,37 @@
  */
 final class GeometryTypeEnumTest extends TestCase
 {
+    /**
+     * Additional ISO geometry types retain their identity and complete classification.
+     */
+    public function testAdditionalGeometryTypes(): void
+    {
+        $expected = [
+            ['BREPSOLID', 'BRepSolid', TopologicalDimensionEnum::VOLUME, null],
+            ['CIRCLE', 'Circle', TopologicalDimensionEnum::CURVE, GeometryTypeEnum::POINT],
+            ['CLOTHOID', 'Clothoid', TopologicalDimensionEnum::CURVE, null],
+            ['COMPOUNDSURFACE', 'CompoundSurface', TopologicalDimensionEnum::SURFACE, null],
+            ['ELLIPTICALCURVE', 'EllipticalCurve', TopologicalDimensionEnum::CURVE, null],
+            ['GEODESICSTRING', 'GeodesicString', TopologicalDimensionEnum::CURVE, GeometryTypeEnum::POINT],
+            ['NURBSCURVE', 'NURBSCurve', TopologicalDimensionEnum::CURVE, null],
+            ['SPIRALCURVE', 'SpiralCurve', TopologicalDimensionEnum::CURVE, null],
+        ];
+
+        foreach ($expected as [$name, $value, $dimension, $component]) {
+            $type = GeometryTypeEnum::from($value);
+
+            self::assertSame($name, $type->name);
+            self::assertSame($value, $type->value);
+            self::assertSame($type, GeometryTypeEnum::tryFrom($value));
+            self::assertContains($type, GeometryTypeEnum::cases());
+            self::assertSame($dimension, $type->topologicalDimension());
+            self::assertSame($component, $type->componentType());
+            self::assertTrue($type->isInstantiable());
+            self::assertFalse($type->isCollection());
+            self::assertFalse($type->isMulti());
+        }
+    }
+
     /**
      * A circular route remains a curve made from point locations.
      */
@@ -112,6 +143,14 @@ public function testGenericMultipartGeometries(): void
     public function testInstantiabilityClassification(): void
     {
         $expected = [
+            GeometryTypeEnum::SPIRALCURVE->name => true,
+            GeometryTypeEnum::NURBSCURVE->name => true,
+            GeometryTypeEnum::GEODESICSTRING->name => true,
+            GeometryTypeEnum::ELLIPTICALCURVE->name => true,
+            GeometryTypeEnum::COMPOUNDSURFACE->name => true,
+            GeometryTypeEnum::CLOTHOID->name => true,
+            GeometryTypeEnum::CIRCLE->name => true,
+            GeometryTypeEnum::BREPSOLID->name => true,
             GeometryTypeEnum::CIRCULARSTRING->name => true,
             GeometryTypeEnum::COMPOUNDCURVE->name => true,
             GeometryTypeEnum::CURVE->name => false,