upgrade/v2312-Developer-Upgrade-Guide.md

@@ -23,6 +23,14 @@
 
 ## Namespace changes
 
+## Rename
+
+### Function object: `WeberNumberReacting`
+
+The Lagrangian function-object class `WeberNumberReacting` is renamed
+as `ReactingWeberNumber` to ensure the consistency with the new Lagrangian
+cloud function object `KinematicWeberNumber`.
+
 ----
 
 [code-patterns]: /coding/patterns/patterns