diff --git a/webnotes/model/controller.py b/webnotes/model/controller.py
index 9f31f9decc..2bc58bec6b 100644
--- a/webnotes/model/controller.py
+++ b/webnotes/model/controller.py
@@ -50,6 +50,8 @@ class DocListController(object):
 		return self._meta
 		
 	def validate_value(self, fieldname, condition, val2, doc=None):
+		"""check that value of fieldname should be 'condition' val2
+			else throw exception"""
 		if not doc:
 			doc = self.doc