By using special characters in pictures you can indicate more precisely how the number should look. For example, you can show that a dollar sign is to be prepended to a number by putting a dollar sign in the picture:

A leading zero indicates that leading space is filled in with zeros:

A plus sign indicates that positive numbers are to be explicitly indicated:

Use parentheses to show that negative numbers should be printed in parentheses:

Other special symbols include L and C, for setting left and center justification, a minus sign to indicate that negative numbers should be shown with a minus sign, and a comma to indicate breaking digits into comma-separated groups of three.