I might be the reason for those warnings ;^)
I had an HT once that had a belt clip. I needed to take the belt clip off for some now forgotten reason, and I put the belt clip mounting screws back in the rig w/o the clip. Well... the idiots that designed the HT made the belt clip mounting holes go all the way thru the case back (such that I couldn't leave them out, or water and dirt would get inside the rig), and that little bit of missing thickness was all it took to crush a component on the PCB below one of the holes (rendering the HT dead).
Every time I see one of those little stickers now, I curse that HT and chuckle...
...R