diff --git a/changelogs/4.0-snapshot.md b/changelogs/4.0-snapshot.md
index ed2606f2d..9d7539981 100644
--- a/changelogs/4.0-snapshot.md
+++ b/changelogs/4.0-snapshot.md
@@ -461,6 +461,13 @@ This version features substantial changes to the network system, improving coher
   - `LeatherPants`
   - `LeatherTunic`
 
+#### NBT handling
+- Serialized NBT byte array caches are no longer stored on itemstacks. These caches were a premature optimization used for network layer serialization and as such were dependent on the network NBT format.
+- Internal NBT usage has been marginalized. It's no longer necessary to immediately write changes to NBT. The following hooks have been added:
+  - `Item->serializeCompoundTag()`
+  - `Item->deserializeCompoundTag()`
+- It's planned to remove runtime NBT from items completely, but this currently presents unresolved backwards-compatibility problems.
+
 #### Enchantment
 - The following API methods have been renamed:
   - `Enchantment::registerEnchantment()` -> `Enchantment::register()`