Below are some fields we should check when we copy one product from another.
1. For Volume # : To add trial product in trial wizard, we need to add value "TRIAL" in Volume # field of product in Multipub.
For webinar products and Event products we are adding date value.
2. For Library #: To link login activity with websites, we are adding short URLs in library # field of product. So that user's login activity can be linked with particular website.
Examples of short URL
grants.ce = grants.complianceexpert.com
grantscape = thegrantscape.com
Reference: https://app.assembla.com/spaces/cbi_websites/wiki/Product_Customization_in_Multipub?mode=edit
Below are unique Library# filed value we used in MP.