Trick/treat and Halloween in general is a new thing in Sweden. And there seems to be a convention that if you are prepared for kids coming, you put up a tag on the door indicating it.
My friend (64 years old) thought it would be a "trick" to put such tags on all the doors in the neighborhood... (No info on the results)
@niclas @jank0 @docpop If the neighborhood kids want some tips from an American on how to properly egg and/or TP a house, I'm happy to do a Zoom call…