Yate maintains three sets of data. The first is the initial contents of the files prior to any modification. You can revert to this version of the data at any time. The second is the current value. This represents the data that will eventually be saved to the files. The third is the current editing state.
Whenever you change the file selection, the editing portion of the main window will change to reflect the contents of the file or files that have been selected. At the same time an editing state can optionally be established. You can undo changes to the editing state or manually update the contents. See Tag Value States for more information.
When a file has unsaved changes the indicator light to the left of the file in the list of files will be red. When the file has no unsaved changes the indicator will be green.
You've probably noticed the round coloured buttons to the left of almost every field in the edit panels. These buttons are function buttons. They are used to reflect the changed state for individual fields. They are also used to access additional functionality for their associated field via a context menu displayed when you click on the button. The function button colours and the complete list of available menu items are described in Function Buttons.
At any given time you can review what changes have been made to the selected files via the View>Changes menu items. The Log Viewer will open with a description as to what has changed in the files since they were first opened.
Additional information: