diff --git a/ChangeLog.d/coding-style.txt b/ChangeLog.d/coding-style.txt
new file mode 100644
index 0000000..b2cff5c
--- /dev/null
+++ b/ChangeLog.d/coding-style.txt
@@ -0,0 +1,5 @@
+Changes
+   * The C code follows a new coding style. This is transparent for users but
+     affects contributors and maintainers of local patches. For more
+     information, see
+     https://mbed-tls.readthedocs.io/en/latest/kb/how-to/rewrite-branch-for-coding-style/