diff --git a/.cspell.yml b/.cspell.yml
index a00b968..f6644a4 100644
--- a/.cspell.yml
+++ b/.cspell.yml
@@ -57,3 +57,6 @@ words:
   - maxlevel
   - replacer
   - Shellcheck
+
+  # Used in newsletters.
+  - Robbert
diff --git a/newsletters/202509-phpcs-4.0-release.md b/newsletters/202509-phpcs-4.0-release.md
new file mode 100644
index 0000000..f2aead5
--- /dev/null
+++ b/newsletters/202509-phpcs-4.0-release.md
@@ -0,0 +1,20 @@
+# PRESS RELEASE
+
+## Highlights of the 4.0 release
+
+* Root rulesets can now overrule config and CLI settings set in child rulesets.
+* Ability to scan files without extension.
+* Less chance on scans failing on parse errors during live coding.
+* Exit code improvements
+* Proper separation of output between STDOUT and STDERR.
+    Piping output to STDOUT will no longer contain progress information or error notices
+* Array properties set in a ruleset file can now extend a potential default value for the property.
+
+
+Other note worthy improvements from the past few months
+* Permalinks to XSD schema
+* The documentation Wiki is now publicly editable.
+
+
+<!-- MAYBE, but probably not appropriate for the release mail, maybe better to move this to the "2 year after take-over" mail Dec 1st -->
+We'd also like to commemorate Robbert Müller, co-maintainer of the PHP_CodeSniffer Composer Installer plugin, who passed away at the age of 46 this July.