Help What's up with my Dark Dragonite card?

Nate The Bug Catcher

Aspiring Trainer
So I am looking at some of my vintage 1st gen cards. And I noticed my dark Dragonite Team Rocket card has a unusual mark next to the R (team rocket logo). The mark is Down slightly below the R symbol and to the right side along the yellow border. The mark Looks like a tiny lightning bolt. None of my other Team Rocket cards have this mark on it. Can anyone help?