The Publish To FTP pulldown causes the program to go out to the FTP web site for the current calendar and merge the calendar entries from this file into the current calendar. This is handy if two people are working on the calendar and you want to update your copy from what they published. Since the login and passowrd are not stored on the copy sent to the FTP site, whatever you have in the current file will be unchanged.
If you did not specify the login and password in the Publish Preferences, you will be prompted for the missing information since the ftp site must be accessed. After the data is merged a popup signals completion. Any errors are put into popups..