Material Description vs Material Type in the Calculator

There are two separate columns in New Construction and Demolition Waste Management Calculator in .xls format: ‘Material Description’ and ‘Material Type’. I assume, that in ‘Material Type’ column I should  put materials such as paper and cartoon packages, timber, plastic packages, glass etc. Since this kind of information seems to be comprehensive when it comes to materials description, I have no idea what kind of additional information I should put in “Material Description” column. I would be really grateful four helpful answer.