De-generalize

docs/source/format/CanonicalExtensions.rst

@@ -251,32 +251,24 @@ Variable shape tensor
    Values inside each **data** tensor element are stored in row-major/C-contiguous
    order according to the corresponding **shape**.
 
-.. _text_data_format_extension:
+.. _json_extension:
 
-Text data format
-=================
+JSON
+====
 
-* Extension name: `arrow.text_data_format`.
+* Extension name: `arrow.json`.
 
-* The storage type of the extension is ``StringArray`` or
+* The storage type of this extension is ``StringArray`` or
   ``LargeStringArray``or ``StringViewArray``.
 
 * Extension type parameters:
 
-  * **media_type** must be a string specifying the
-    `IANA registered <https://www.iana.org/assignments/media-types/media-types.xhtml#application>`_
-    text data format stored in the array.
+  This type does not have any parameters.
 
 * Description of the serialization:
 
-  The metadata must be a valid JSON object providing a **"media_type"** key
-  plus an optional **"metadata"** key for additional application specific
-  information such as schema or notation dialect.
-
-  - Example: ``{ "media_type": "application/json" }``
-  - Example: ``{ "media_type": "application/xml" }``
-  - Example: ``{ "media_type": "application/yaml", "metadata": { "key": "value" } }``
-  - Example: ``{ "media_type": "text/csv" }``
+  Metadata is an empty string.
+  - Example: ``""``
 
 =========================
 Community Extension Types