Microsoft Excel contains a nifty category of number formats called Special. The Special category contains the following four number formats that may interest you.

• Zip Code: Retains any leading zeros in the value (important for zip codes and of absolutely no importance in arithmetic computations). Example: 00123.
• Zip Code + 4: Automatically separates the last four digits from the first five digits and retains any leading zeros. Example: 00123-5555.
• Phone Number: Automatically encloses the first three digits of the number in parentheses and separates the last four digits from the previous three with a dash. Example: (999) 555-1111.
• Social Security Number: Automatically puts dashes in the value to separate its digits into groups of three, two, and four. Example: 666-00-9999.

These Special number formats really come in handy when creating databases in Excel, which often deal with stuff like zip codes, telephone numbers, and sometimes even Social Security numbers.