diff --git a/data/fwupd.conf b/data/fwupd.conf
index f6b85ce7b..0e77e23ad 100644
--- a/data/fwupd.conf
+++ b/data/fwupd.conf
@@ -8,9 +8,11 @@ DownloadURI=https://s3.amazonaws.com/lvfsbucket/downloads/firmware.xml.gz
 EnableOptionROM=true
 
 # Allow blacklisting specific devices by their GUID
+# Uses semicolons as delimitter
 BlacklistDevices=
 
 # Allow blacklisting specific plugins
+# Uses semicolons as delimitter
 BlacklistPlugins=
 
 # Turns on support for running the test suite