diff --git a/.gitignore b/.gitignore
index 1f4f86d08..9fddbdee7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -70,3 +70,6 @@ Thumbs.db
 
 # Upgrade staging directory
 _upgrade_staging/
+
+# Research comparison (not tracked)
+/todo/research/np3-4.md