Most of the items in the File menu are standard for a Macintosh application. This menu contains items to open a file, close a file, save the changes to a file, reverting a file, and quitting the program. If you have started to spell check a file and you suddenly remember that you forgot to activate a dictionary, you can use Revert to put the spell checking operation in its initial state. Then, activate your dictionary and hit Start.
The Open Clipboard item will let you open the clipboard for spell checking. When spell checking the clipboard, the Save item becomes Save Clipboard so you can save your changes back to the clipboard. This is useful if you want to spell check just a small portion of a document. You can copy the text to the clipboard, check its spelling, save the result back to the clipboard, and then paste the result back into your document.