The following control procedures over sales transactions are prescribed by the Harlan Company:

1. Credit department approval of credit sales.

2. Sales invoice for each shipping document.

3. Internal verification of prices, terms, and accuracy of sales invoice.

4. Prenumbered sales invoices.

5. Agreement of daily sales summaries with recorded entries.

6. Authorization of prices and terms.

7. Monthly statements are independently mailed to customers.

8. Reconciliation of control accounts and subsidiary ledgers.

Required:

For each control procedure

a. Indicate the function and the specific internal accounting control objective of each procedure.

b. Identify the internal accounting control principle that is involved.

c. Identify an error or irregularity that may be prevented or detected.

d. Indicate a specific test of transactions that may be performed to determine whether each control is operating as prescribed.