Number of files that ExifTool knew it did not need change. Note that ExifTool (at least as of v12.70) only realizes it doesn't need to change a file if you are clearing an already empty value.
Number of files updated by ExifTool. Note that this does not mean any field values were changed from prior values.
OptionalwarningsNon-exceptional warnings from ExifTool, like "Error: Nothing to write", or "Nothing to do."
Any invalid tag names or values will cause Errors to be thrown.
Number of files created by ExifTool