Our commercial janitorial agreement has us emptying trash cans, not "removing trash". The reason for the distinction is that, if something looks like trash, but is not in a can, and is not labeled "trash", it's a good idea to not toss it. We'll toss something if it's clearly labeled, as a favor, but not commit to it, to avoid ambiguity.
But, in this world, ambiguity is hard to avoid. 
An example comes to mind. We were cleaning a 9-story mid-rise, a few years back. My crew came across a large computer rack (the kind you see in the server closet, with lots of devices on it), with many boxes of trash stacked around and on it, and a post-it note, "trash". My crew took multiple trips to the dumpster, and a bit of extra effort manhandling the rack into the elevator. Received an irate call from the client early the next morning, asking why we'd removed the rack. OBVIOUSLY, the note only referred to the boxes, not the rack that the note was affixed to.
Another occasion was at a radio station. We tossed a box that was sitting atop a trash can. Again, the irate client wondered why. It seems that the expensive microphone that arrived in the box had arrived damaged; they needed the box to prove that it was damaged while in route. Why would we think that a box sitting on top of a trash can was indeed trash?
Finally, a landscape architect. Picture a wicker trash can, sitting by the front door. We had our regular crew out sick, and a replacement cleaning the building. Turns out that the trash can by the front door was not for trash at all; it held the Mylar drawings set out for pick-up by the blueprint company. Sometime earlier, the client had left a note for our regular crew to not empty that can, but had not mentioned it to my office or during our regular quality assurance visits; our crew assumed that the client would do so, so that the information would find it's way onto our job paperwork. Turns out, Mylar drawings are expensive.
Sorry. Just have to vent occasionally.
