Hi Slav!

Thanks for asking. You pointed out one thing that must be fixed.

Normally you would do this with filter and group edit.
1) set qso list/filter to find "include" contest name or part of it at "Remarks" (remarks is actually commnet to qso, this bug is already issued, but not fixed yet)
2) when you get qso list including wanted contest name you choose qso list/file/group edit. Select "contest name" and write new content to it that will be written to all qsos listed.

Just that now there is not a selection "contest name". That must be fixed.

At present time change is only possible with "SQL console". Type command to upper window and press arrow on up left corner (1st icon left).
Type only one line at time to upper window.

First find qsos you want with command:
select * from cqrlog_main where remarks like "%RTTY RU%"

Here the comment for qso includes text RTTY RU, change it by your needs.

Then set the contestname with command:
update cqrlog_main set contestname = "RTTY RU-CONTEST" where remarks like "%RTTY RU%"
(note that contestname max length is 40)

Then do the first command again. You find it with arrow left (second icon), after that again the arrow (1st icon from left) to execute command.

If the list looks good and there is contestname you maybe want then clear comment for qso field with command:
update cqrlog_main set remarks = "" where contestname = "RTTY RU-CONTEST"

And finally check results with command:
select * from cqrlog_main where contestname = "RTTY RU-CONTEST"

2 last ones are optional only if you want to clear comment for qso.

BUT:
DO BACKUP FROM LOG FIRST before trying anything.

SQL commands do not have "oops"-button.
Same with Group edit. With that you can also very easily destroy whole log.