diff --git a/validation_functions.py b/validation_functions.py
index c4c270c..45c0291 100644
--- a/validation_functions.py
+++ b/validation_functions.py
@@ -24,6 +24,7 @@ def iso_date(field, value, error):
 
 def valid_money_amount(field, value, error):
     try:
+        # value is string, check formatting by parsing as float
         float(value)
         return True
     except (ValueError, TypeError):