Been around for 29 years and never heard of such a thing.
A lot of boogie events and competitions that drew participants from all over would do that. As part of registration, they would have a rigger check all gear for whatever recent set of gear problems had been happening, like leg strap replacements, soft 3-rings, or whatever. Or just checking general safety items like riser wear and reserve seals. And then they would put a colored or coded cable tie on the handle to show that the rig had been inspected and passed.
I've also seen this used as a means of showing that the boogie fee was paid, so that as people are boarding the plane, the DZ employee can scan all the jumpers and see that they're not sneaking on for free.
Many jumpers would not remove those ties after each boogie, and would accumulate quite a collection, as a sign of how well-traveled they were. They became like a badge of honor.
Nowadays they seem to use those plastic hospital wrist-bands instead. Want to drink the free boogie beer? Let me see your wrist band, buddy!