Create a new Purchase Order Document Type

If you have more than one company code, you might want to define a new document type and number range to differentiate between the two company.

Define a new number range not in used
OMH6 - Number Ranges for Purchasing Documents

Copy the NB - Standard PO to e.g. ZB
OMEC - Define Document types

Maintain :
Text for Document Header/Item
Text for Document Supplement
OMF6 - Messages Header Texts