Open Purchase Order = Open Goods Receipts ( Selection parameters WE101)
This two parameters determined what information is shown:
selection parameter
scope-of-list parameter
The configuation transaction code is OMEM
You can define additonal selection parameter for your users as well as untick those fields which you does not want it to be printed.
Your can have the Purchasing Documents by :-
ME2L - Vendor
ME2M - Material
ML93 - Service
ME2K - Account Assignment
ME2C - Material Group
ME2B - Requirement Tracking Number
ME2N - Purchase Order Number
ME2W - Supplying Plant