There are at least four of these, one on each planet is all I've found (so far). The one on Nessus is the lost sector where Failsafe is at (Exodus Black) and is in a trailer in the lost sector in close proximity to the loot box. There is another on the EDZ and it's in the lost sector that features both Cabal and Fallen, and you can get there via The Gulch, or the alternate entrance that isn't marked in the Winding Cove, this one is located across the creek area from the loot box on a ledge. The one on Titan is located in the Solarium; after you go through the hole in the multi-colored wall, take the path to the left of the "pool" almost to the end; you'll get to a "bridge/stairs" where hive spawn, turn around and this one will be by the doorway you just walked in through, on the left side of the catwalk over your head. The last one is in The Rupture on IO lost sector that has the Vex Hydra (it's the farthest lost sector in that area from Asher, far right hand corner from where the public event spawns. Clear this lost sector and from the area around the loot box, turn left/back; most everyone knows that there is a room on the back left from the loot box that you can get to easily, but there is another room that is accessible through the front of the "clock" (there's a hole in the low center of the clock that has a platform extending out through it you can jump on, go through the hole and turn right, go to the room in the back right and there is a box that can be scanned like the other items. All of these items disappear after you've scanned them once, they don't move and they always are located in the same area (I've scanned all with all three of my characters and have taken friends there as well). Not sure what, if anything, we get out of it, but am still looking for more locations with similar items before the reset at the end of the faction rally, as none of these items were present before the rally, I don't expect them to be after. Good luck and reply if you have any questions or find other locations!