Does anyone have a source in how this can be used as a scoreboard? I only ask such a specific question because it seems like a very specific object to recognize

Does anyone have a source in how this can be used as a scoreboard? I only ask such a specific question because it seems like a very specific object to recognize it as. I assume there would be some indicator placed next to a symbol around the edge but was a bit disappointed to see nothing describing it in the article. Maybe too obvious to state?