stevenschlansker commented on code in PR #3714:
URL: https://github.com/apache/fory/pull/3714#discussion_r3352757879


##########
docs/guide/java/row-format.md:
##########
@@ -113,6 +113,78 @@ Row format is ideal for:
 - **Data pipelines**: Processing data without full object reconstruction
 - **Cross-language data sharing**: When data needs to be accessed from 
multiple languages
 
+## Schema evolution
+
+Enable `.withSchemaEvolution()` on a row, array, or map codec builder to read 
payloads written
+by older versions of the same bean. Writing always uses the current version; 
reading detects
+the payload's version from a strict hash at the head of the payload. Java only.
+
+Annotate fields added after v1 with `@ForyVersion(since = N)`:
+
+```java
+@Data
+public class Person {
+  private String name;
+  private int age;
+
+  @ForyVersion(since = 2)
+  private String email;
+}
+```
+
+A v1 payload (with `name` and `age` only) decodes to a `Person` whose `email` 
is `null`.
+Primitive fields added later default to `0`, `0.0`, or `false`. If a class 
adopts versioning
+after its v1 is already in the wild, set `@ForySchema(baseVersion = N)` so 
unannotated fields

Review Comment:
   this is nonsense?



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