Adding documents to material master for internal purpose

Hi Gurus,

I want to add a documents to material master which should not be printed on PO that means only for INTERNAL PURPOSE

My scenario is we  already have some documents which are usually printing on PO.(external purpose)

But i want to add some documents to material master only for internal purpose,that means should not be printed on PO.(Internal purpose)

please help me out.

thanks in advanvce