The NCAA shut down the idea of using Twitter hashtags on the field before it ever really got going.
Mississippi State has used a hashtag in the end zone for games (see above) and it had popped up on fields at spring games here and there. While it seems a little gaudy, it's not the worst idea. Although, the first time a company decided to get in on the action and we saw #McDonaldsBigMacSale in an end zone, it wouldn't seem so great. But the idea of using hashtags on the field seemed like something that was going to start spreading.
No matter, the NCAA has stepped in and stopped it, outlawing hashtags on the field.
Other rules were added. Numerals on jerseys must have a distinct color from the jersey itself. Towels must be solid white and measure between 4x12 inches and 6x12 inches. All eye shields including glasses and goggles must be clear and not tinted. Pretty mundane stuff.
The hashtag rule is the most interesting one. The rule also outlaws website URLs on the field. The move seems pretty unnecessary and just a way for the NCAA to put an end to all fun. Then again, even though hashtags on the field seemed like a decent harmless idea, the games will probably survive without them.