Accounting Information Systems 7th Edition by Cynthia Heagy,Constance Lehmann

Exercise 5

Some accounting transactions have source documents whose preprinted numbers can be used effectively as audit trail reference identifiers. The preprinted number on other source documents evidencing transactions cannot be so used.
Required:
a. Identify those document identifiers that are useful components of an audit trail.
b. Identify other common document identifiers that are not.
c. What two characteristics do useful reference identifiers possess?