A family of Microsoft word processing software products for creating web, email, and print documents.
To add to what Doug has said, if there has ever been text in the alternative headers, it will remain there even when the header is not in use. You may need to enable both Different First Page and Different Odd and Even in order to see them. Note that the "primary header" (the one used if you don't have either of the above options enabled) becomes the Odd Page Header when you enable Different Odd and Even, so there are really only three headers to deal with. If you have more than one section, you may well have three different headers in each. And, if a section contains fewer than three pages, you will need to temporarily add pages in order to display all the headers.