"That's not your problem" is a cue I developed with Elka, because of course I can't possibly take peoples' advice when they say to keep cues simple. She's smart enough, I feel that simple cues don't always get the point across. Or, they come to mean a broad category, and don't really apply to the next category.
So, while "Leave it" would suffice for most dogs, for Elka, "leave it" refers to items, objects, and wildlife in the yard.
"That's not your problem" applies to other dogs, either in view or barking blocks away. It applies to people walking past on the sidewalk across the street, car doors closing, people coming home next door, etc. The longer phrase seems to assure Elka that yes, I do see the issue, and she can leave it.
I established the cue using redirection, essentially. There is a typical chain of events that occurs: 1. noise outside 2. Elka growls, piloerects, starts grumbling, or actually barks (or a combination of a few) 3. I call her to me or use "Look at me" if we're already together on the couch 4. I assess what it is (if I didn't recognize right off) 5. I tell her "That's not your problem" 6. Elka is expected to go lay down, or play with a toy, or whatever. Just not continue barking and growling or whatever.
We have to attain number 6 every fall anew, when the college kids move in. We share the bottom of our driveway with the house next door, so their driveway and door noises sound very close and probably echo. The three houses across the street are also rentals, of varying capacities. But our street is very, very quiet in the summer and so Elka relaxes and essentially forgets that people will be all around us.
Calmness and patience are essential to the success of "That's not your problem". You yourself have to carry off that you do not care. You aren't wasting time and attention on it. However, I also don't want to discourage Elka's alertness entirely. So, she's allowed to (quietly!) acknowledge that Something Happened. But it is essential that she recalls or responds to "Look at me" when I ask. She gets rewarded for both of those things, verbally and on a random schedule for food or play reward.
Elka gets rewarded in the same way for calming herself down after "That's not your problem" has been uttered. If she's gone to lay down quietly, I'll pet her extensively rather than rile her up with a toy, but that's just part of the situational assessment.
We also encounter a little bit of intelligent disobedience here. You see, our doorbell doesn't work. Never has. But people, sometimes, will "ring" the bell and wait, rather than trying to knock (others seem to catch on). If I'm in the kitchen, I won't know somebody's on the porch, but Elka still does. If I don't investigate, she will not listen to the cue, because it is, in fact, her problem that somebody is on the porch.
But when she stands down, she stands down.