diff --git a/README.md b/README.md
index 613a40b..acea451 100644
--- a/README.md
+++ b/README.md
@@ -149,7 +149,7 @@ sudo chown -R bridgehead:root . /etc/bridgehead
 sudo vi /etc/bridgehead/bbmri.conf # Modify to include national node name and admin contact details
 ```
 
-For an ECDC/EHDS2 installation, you will also need to copy your data in a ```.csv``` formatted file to ```/srv/docker/bridgehead/data```. Make sure it is readable by all.
+For an ECDC/EHDS2 installation, you will also need to copy your data in a comma-separated value (CSV) formatted file to ```/srv/docker/bridgehead/data```. Make sure it is readable by all. Only files with the ending ```.csv``` will be read in, all other files will be ignored.
 
 If this is not an ECDC/EHDS2 installation, then download your site specific configuration repository:
 ```shell