Not needed, but would be nice.... I have learned how to tag the photos I like, then double check my tagging. I then I go back to the contact sheet, change the search box to "un-tagged photos", select them, then delete. Works fine!
Is there quick way to initially "color" all the photos, perhaps with red, and when I tag photos, have the color vanish automatically?
This way, when I view the full contact sheet, the photos I am going to delete will have a red box around them, in addition to not having a check mark from tagging. This would be more intuitive to me.