IMatch supports multi-level Undo for many operations. This allows you to easily undo a recent change when you make a mistake.
To access the Undo function, go to Edit > Undo.
The undo mechanism in IMatch keeps track of changes you make, e.g., renaming a category, moving images between categories, changing metadata and so on. If you make a mistake, go directly to the Undo command or press Ctrl+Z to undo your recent change or changes.
Certain commands and features clear the Undo menu. For example, if you remove a file from the database, IMatch will clear the Undo menu because it can no longer guarantee that the "undoable" operations will still work. For example, if the Undo menu contains an undo for a category assignment, but you delete the files from that category from your hard disk, it will no longer be possible to undo the category assignments. The files just no longer exist on your disk.
You should thus always use Undo immediately after you noticed a mistake or problem.
Some operations and commands cannot be undone. This includes operations like deleting, moving, copying or relocating files and folders, whether you do it directly in IMatch or via drag and drop.
Use Reject instead of deleting files. This allows you to easily undo the command, or to physically delete all rejected files at once.
See the corresponding help topic for details.