Free fields on BSEG

Question

Hello Expert,
I have to add 3 new fields on BSEG. I remember that the fileds XREF1, XREF2, and XREF3 were free fields. But I have seen that XREF3 is used by MM module.
The fields, i need,  should be available for transaction FB01 to post invoice from another system.
Can you give me some suggestion?
Thanks. Bye.

Answer 1

Hi Josy
In order to add new field to the table BSEG you have two possibilities:
- Add the required fields in the coding block.                        
   Path in the implementation guide is                                 
   Financial Accounting                                                
     -> Special Purpose Ledger                                         
        -> Basic Settings                                              
           -> Maintain Coding Block.                                                                               
(Transaction   > OXK3)                                                                               
- Using an "Append structure" for table BSEG.
The aspects to be      considered are described in R/3 Online Documentation. You can access
   R/3 Online Documentation from any R/3 screen -> Help -> R/3 library.
   In R/3 Library, go to                                               
   -> BC - Basis Components                                            
     -> ABAP Workbench                                                 
       -> BC ABAP Dictionary                                           
         -> Tables                                                     
           -> Append Structures.                                       
However, with this option on posting a document, the field is not    automatically added to the standard dynpros. Any modification must   be included in as a change to the standard system.                     
Here is also information from development:  include technology is a suitable method to isolate SAP standard fields from customer fields in transparent tables.                            
It is not suitable for cluster tables like BSEG.                                                                               
The critical difference between transparent tables and cluster tables is that for cluster (and pool) tables the order of fields on        the database is always the same as the order in the dictionary.        
For transparent tables an arbitrary translation between these orders can be achieved by the R/3 data base interface.                                                                               
This implies that new fields can only be appended to table BSEG.       
Any insertion inbetween existing fields or any change of field order would lead to a database conversion which is unacceptable     for huge tables like BSEG.                                             
So event with an include structure for your customer fields   you would be in the situation that                                                                               
a.) with the include at the end of BSEG you would be able to insert    
fields here, but new fields delivered by SAP and inserted              
in front of the include would lead to conversion if                    
your include is non-empty.                                             
New fields appended by SAP after the include would lead to situation   
b.) with the include within BSEG, any new fields entered               
into the include structure would lead to a conversion.                                                                               
So an include can never solve the conflict of SAP and customer   adding new fields to a cluster table.                                                                               
Therefore SAP and customer will always append fields to the end of  BSEG directly.
During the upgrade the conflict has to be solved using   transaction SPDD (dictionary adjustment).                              
During the upgrade(prior to activation) you will be prompted to run SPDD and see all your customer fields and possibly new SAP fields.          
Here you can assure that your fields which are a formal modification will be retained in BSEG and new SAP fields will be appended to the  end of current BSEG definition behind your user fields."      
Hope it helps
kind regards
davide