diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index b55b550..ea0dfdd 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -2,6 +2,10 @@
 
 ## XMLUnit.NET 2.7.3 - /nor released, yet/
 
+* add a new `${xmlunit.isDate}` placeholder
+  [#31](https://github.com/xmlunit/xmlunit.net/pull/31) by
+  [MilkyWare](https://github.com/MilkyWare)
+
 ## XMLUnit.NET 2.7.2 - /Released 2020-03-08/
 
 * the XPath values for comparisons resulting in `CHILD_LOOKUP`