diff --git a/aip/general/0136.md b/aip/general/0136.md
index dbb52c26f..c1edb8a34 100644
--- a/aip/general/0136.md
+++ b/aip/general/0136.md
@@ -51,7 +51,7 @@ services. The bullets below apply in all three cases.
     considered), a custom `CreateBookLongRunning` method could be introduced.
 - The HTTP method **must** be `GET` or `POST`:
   - `GET` **must** be used for methods retrieving data or resource state.
-    - `POST` **may** be used for data retieval methods if the request payload could
+    - `POST` **may** be used for data retrieval methods if the request payload could
       exceed URL size limitations, thus requiring a `body`.
   - `POST` **must** be used if the method has side effects or mutates resources
     or data.
@@ -159,6 +159,18 @@ read data have first-class concepts in some clients (DataSources in
 Terraform) and clearly indicate to a user which methods can be called
 without risk of runtime impact.
 
+Allowing `POST` to be used for requests which would otherwise be made using
+`GET` is a convenience:
+
+- It avoids large query strings leading to requests which violate URL size
+  limitations.
+- It allows clients to implement a single way of serializing request data, or
+  at least avoids them from having to implement complex rules for repeated
+  fields etc.
+- It allows RPCs which might normally be simple to still contain data for
+  complex situations where that data may not be representable via query
+  parameters.
+
 ### Disallowing prepositions
 
 Generally, method names with prepositions indicate that a new method is being