diff --git a/README.md b/README.md
index 5c27aa9..d9c94b4 100644
--- a/README.md
+++ b/README.md
@@ -125,6 +125,21 @@ usgsxplore search declassii --filter "camera=KH-9 Lower Resolution Mapping Camer
usgsxplore search declassii --filter "camera=L & DOWNLOAD_AVAILABLE=Y"
```
+**Note**: If you don't know what filters are available, they will be printed to screen when typing any (wrong) value. For example,
+```bash
+usgsxplore search declassii -f "whatever=?"
+```
+will print all metadata filters that can be used for the "declassii" dataset.
+
+
+
+```bash
+usgsxplore search declassii -f "camera=?"
+```
+will print all possible values for the filter "camera".
+
+
+
### Downloading
```bash