All but one file in each group

[dcwul62]

I am not sure about the "All but one file in each group"-feature.
In "Selection Assistant" (below "Mark by group") that option is selected.

However, when deleting duplicate files, Duplicate Cleaner warns that all files in a group may be deleted.
I can then check out those groups and correct matters. Pheww...

But then I am a bit puzzled, should Duplicate Cleaner not automatically deselect one file in those groups?
I have to go thru all the groups myself now. Quite a number. because of wrong copying, or the modified time stamp that is added to the file is slightly different, e.g. one file has an added timestamp:
file name blah blah......... 150150.jpg the other file :
same file name blah blah.. 150151.jpg
same group, same size, everything else is the same.

Q: How/when will this "All but one file in each group" feature work?

Thanks!

Example

[DigitalVolcano]

It should leave (or unmark) one file in each group - check you didn't have 'Leave existing marks unchanged' selected.

[dcwul62]

Wonderful! Thank you very much indeed.
That solved a lot. That, plus... check 'Shortest file names in each group'.
Often, long file names include a description.

Anyway, thanks again!