The Check Clearing for the 21st Century Act (Check 21 Act) allows recipients of paper checks to create a digital image of the original check, eliminating the need for further handling of the actual check. The Federal Reserve Board has created a consumer guide, Consumer Guide to Check 21 and Substitute Checks, which can be found on the Federal Reserve's Web site (www.federalreserve.gov) by searching the guide's title. Locate the guide to answer questions about Check 21.

a. What is a "substitute check"? Does it constitute a legal copy of the check?

b. How does Check 21 affect the payment of your checks?

c. Do banks have to return actual cancelled checks? Explain.