Deleting a QSO mid-contest in a multi-op situation
If you need to delete a QSO during a contest it is recommended you do NOT use the menu option Edit | Delete QSO as this will have the consequence of deleting the QSO in the log at your operating position ONLY but not network-wide.
Instead, replace the callsign of the QSO you wish to delete with the station callsign that you specified in pre-contest. For example, if you are using the callsign G6PZ and you wish to remove QSO #404 with CE1ABC, replace the CE1ABC callsign with G6PZ. Later, when it comes to merging and exporting the logs, there is an option to delete all QSOs with yourself from the log.
Even a better solution is to dupe the previous QSO, you'll have one more dupe but score and multipliers will be correct.