Hi,
For numbering series of documents, prefixes and suffixes are relevant for printing only. For numbering series of master data, prefixes and suffixes help avoid overlaps with other series.
For more information, you can refer this help link http://help.sap.com/saphelp_sbo900/helpdata/en/45/06b9797d720487e10000000a155369/content.htm?frameset=/en/45/06b8517d720…
Hope this helps,
TVSon