Allocations - mandatory fields
A value must be supplied for:
-  
                              			            
                              
Allocation Definition Code - payload element
<VSsrfmscAld_AldDefnCode> 
except for the Query method where it is optional.
In addition, if creating or amending Allocation Step data, or using the DeleteChildData method, then:
-  
                              			            
                              
Allocation Sequence Number - payload element
<VSsrfmscAld_AldSeqNum> 
must be supplied.