The description for LIPS-EAN11 in SE11 is "International Article Number (EAN/UPC)", so I'm not sure what you're calling it "contract".
To my knowledge, EAN/UPC is usually stored in the material master. So I'm also not quite sure why it's entered manually by someone in the delivery. If a decision was made to "re-purpose" this field for some custom data then it was a bad decision IMHO. You might need to review the design with the functional consultant.