The format painter allows you to copy formatting (including states) from one object and apply it to another. So, for example, you can copy formatting from one button to another, one character to another, or one text box to another.
However, you won't be able to use the format painter to copy formatting from part of the text in one box to text in another box.
Tip: The source object and destination object don't have to be the same type. For example, you can use the format painter to copy formatting from a button to a caption, from a marker to a shape, etc.