diff --git a/silo.py b/silo.py
index 99430d6..ec041b7 100644
--- a/silo.py
+++ b/silo.py
@@ -15,7 +15,7 @@ def pointdata(variables,
     """Request point data from SILO.
 
     Args:
-        variables: list containing variable name strings
+        variables: list of variable code strings (see variable info below)
         api_key:   SILO api key
         start:     start date (yyyymmdd)
         finish:    finish date (yyyymmdd)