diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index ad007c3dd..6b3eff0d8 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -1,4 +1,12 @@
-# Next Release
+# Release v0.4.0
+
+## Highlights
+
+- New feature: downscale regional timeseries data to subregions using a proxy variable
+- Improved features to support aggregation by sectors and regions: support weighted-average, min/max, etc.
+  (including a reworked tutorial)
+- Streamlined I/O: include `meta` table when reading from/writing to xlsx files
+- Standardized logger behaviour
 
 ## API changes
 
diff --git a/pyam/core.py b/pyam/core.py
index 4628de2f1..d4bd0c207 100755
--- a/pyam/core.py
+++ b/pyam/core.py
@@ -1263,7 +1263,7 @@ def to_excel(self, excel_writer, sheet_name='data', iamc_index=False,
 
     def export_metadata(self, excel_writer, sheet_name='meta'):
         """Deprecated, see :method:`export_meta()`"""
-        # TODO: deprecate in next release
+        # TODO: deprecate in next release (>=0.5.0)
         deprecation_warning('Use `export_meta() instead`!')
         self.export_meta(excel_writer, sheet_name='meta')
 
@@ -1286,7 +1286,7 @@ def export_meta(self, excel_writer, sheet_name='meta'):
 
     def load_metadata(self, path, *args, **kwargs):
         """Deprecated, see :method:`load_meta()`"""
-        # TODO: deprecate in next release
+        # TODO: deprecate in next release (>=0.5.0)
         deprecation_warning('Use `load_meta() instead`!')
         self.load_meta(path, *args, **kwargs)