Initial extension (#80)

* Initial extension
* Updates from editors' review
* Editors suggestion

docs/index.md

@@ -1,5 +1,6 @@
 # OCFL Community Extensions
 
+  * [Initial Extension](initial.md)
   * [0001: Digest Algorithms](0001-digest-algorithms.md)
   * [0002: Flat Direct Storage Layout](0002-flat-direct-storage-layout.md)
   * [0003: Hashed Truncated N-tuple Trees with Encapsulating Directory for OCFL Storage Hierarchies](0003-hash-and-id-n-tuple-storage-layout.md)

docs/initial.md

@@ -0,0 +1,45 @@
+# OCFL Community Extension `initial`: Initial Extension
+
+  * **Extension Name:** `initial`
+  * **Authors:** OCFL Editors
+  * **Minimum OCFL Version:** 1.0
+  * **OCFL Community Extensions Version:** 1.0
+  * **Obsoletes:** n/a
+  * **Obsoleted by:** n/a
+
+## Overview
+
+This extension allows indication that the semantics of a particular extension takes precedence over all other extensions. It ensures that the special extension name `initial` is a registered extension name and thus that an extension directory `initial` is also valid in both objects and storage roots.
+
+An extension directory MAY contain an `initial` extension identified by the extension directory name `initial`. If it exists, the `initial` extension specifies another extension that MUST be applied before all other extensions in the directory.
+
+The extension configuration file indicates the functional extension to be applied first by specifying that extension's name in the `extension` parameter (not `initial`). This extension can be used to address otherwise undefined behaviors, such as:
+
+  * Should extensions be applied in a specific order?
+  * Is an extension deactivated, only applying to earlier versions of the object?
+  * Does one extension depend on another?
+
+## Parameter
+
+  * **Name:** `extension`
+    * **Description:** The name of the extension to be applied first
+    * **Type:** string
+    * **Constraints:** Must be a valid extension name
+    * **Default:** Not applicable
+
+## Example
+
+The following `config.json` configuration file indicates that the extension named `NNNN-functional-extension-name` should be applied first.
+
+```
+{
+    "extensionName": "initial",
+    "extension": "NNNN-functional-extension-name"
+}
+```
+
+## Revision History
+
+| Date | Description |
+| ---- | ----------- |
+| 2024-09-19 | First published |