Return values from MDS staging stored procedure

I am learning about MDS 2012 and how to load data from stg table to mdm entities. I loaded data in stg table with appropriate values and executed code below

USE [MDS]
GO

DECLARE @return_value int

EXEC @return_value = [stg].[udp_TestTable_Leaf]
  @VersionName = N'VERSION_1',
  @LogFlag = 0,
  @BatchTag = N'test'

SELECT 'Return Value' = @return_value

GO

This returns value 6 and does nothing. I am unable to load this data. The only way I can start batch from UI. This does not give me any error codes that are listed athttp://msdn.microsoft.com/en-us/library/ff487022.aspx

When I add BatchID to above code, it gives me return value of 7 and message that I cannot provide BatchTag and BatchID at the same time. I am wondering what are the return values?

Rajendra