santosh,
"Reference" functionality, in text determination seems to not work!
I have tested the below -
In VOTXN, for that text condition type, in the text procedure which is assigned to the billing type; the field reference is activated.
Created sales order
created delivery
created billing document - At header level the text maintained in the sales order has populated in the billing document - OK
Now, change the text in sales order
Check the billing document - the text has not changed!
With "reference" activated for this text condition type; according to SAP, if the text is changed in the sales order, then it should automatically change in the billing document too.
But this is not happening.
Could you please test and let us know?