Postal clerks need knowledge in the following areas:

• Customer and Personal Service: Providing special services to customers based on their needs.
• English Language: The meaning and use of the English language.
• Mathematics: The rules and uses of numbers.
• Sales and Marketing: The methods for selling products and services.
• Clerical: General office work such as filling and storing information.
• Computers and Electronics: Computer hardware and software.
• Transportation: The methods and costs for moving people, goods, and materials.