"A material company has an information system used by its clerks to manage the material purchases for contractors. A contractor buys materials by taking them to the checkout desk for contractors. After logging on the system with a staff account, the clerk enters the contractor's name into the system. The system displays the contractor's information, including current credit standing. The clerk then opens up a new ticket (sale) for the contractor. Next, for each item, the clerk scans in the item to be purchased. The system finds the price of the item and adds the item and its quantity to the ticket. At the end of the purchase, the clerk indicates the end of the sale. The system compares the total amount against the contractor's current credit limit and, if it is acceptable, finalizes the sale. The system creates an electronic ticket for the items, and the contractor's credit limit is reduced by the amount of the sale. Some contractors like to keep a record of their purchases, so they request that ticket details be printed. Others aren't interested in a printout."

Based on the above narrative, answer the following questions:

(4.1) Provide a list of all nouns that you identify in the above narrative and indicate which of the following five categories that they belong to: (i) domain class, (ii) attribute, (iii) input/output, (iv) other things that are NOT needed to remember, and (v) further research needed. (7 marks)