Anyone who sticks sticky labels on PVC insulated cables needs to be shot.
It may seem like a good idea to put the label on, and it may seem like it sticks just fine, but in less than a year’s time the glue will have degraded to a slimy goop that causes the label to slip down the cable and leave a veritable filth-magnet in its place. I have actually thrown away otherwise perfectly good network cables rather than try to clean the muck off — and I’m someone who will happily re-terminate busted UTP connectors.
If you need to mark the cable in some way, by all means mark it. Permanent markers are fine, as is heat-shrink labelling. But if you use a sticky label, sellotape, electrical tape, or anything else self-adhesive, do so in the knowledge that one day, I will inevitably shuffle off this mortal coil. And when I do, I WILL HAUNT YOU FOR THE REST OF YOUR DAYS.