The 'O' tag contains the number of errors that occurred during recording. If it is zero, the recording can be safely considered error free. The higher the value, the more damaged the recording is. If this is an - edited recording, the number of errors is that of the edited recording.
+ edited recording, the number of errors is that of the edited recording, if + the index of the original recording contains error indicators (i.e. the + original recording's index was created with VDR version 2.7.2 or later). + Otherwise it's the number of errors in the original recording.