Why am I so damn Twitchy?

I just noticed the other day that Coke has started listing the caffeine content of their drinks on the side of the container. Not in the regular nutrition facts or in the ingredients, but in tiny little writing on the side of the bottle, a little over from that other business. Drinking a can of Pepsi Max this morning, (Max apparently meaning you are drinking twice the caffeine content of a regular Pepsi (remember Jolt? Like the original Jolt cola? That shit was gross)) I decided to look if they listed the content like Coke does now. In fact, they do, but on this can, it's right after the ingredients. Probably a spacing issue, or else I'm sure they would have relegated it to the outermost part of the can, which makes no sense because it's round, but you know what I mean. Anyway, I started thinking. Was this just something that these companies decided to do on their own? Taking responsibility for the things they put into the popular sodas they produce? Or was this an act of government, forcing them to disclose the information, which they've neglected to do for so long, yet everyone knows there's caffeine in there? I figured that since it appeared on the cans out of nowhere, seemingly, there was probably the government mandate part I have theorized to disclose the content on the can. This was probably because of some concerned mothers or fathers that want to know exactly how much caffeine their ultra-hyper kid is actually consuming. Well, I couldn't find anything after researching for five good minutes, so I got bored and quit searching. Anyway, I found it interesting, and I think my suspicions that their hands were forced to disclose the information are correct, so we'll assume this is all true.