In other words, you can't call your beer an Irish stout unless it was actually brewed in Ireland. A few years ago, ATF cited its geographic rules when it banned the Victory's HopDevil IPA label. ATF gave both those brews the green light. Brewers sometimes complain, but they rarely battle. Ironically, experts say the ATF's own fear of a fight is behind its acceptance of foul-language beer labels.
Obscenity is very subjective.
I had one label that, initially, they weren't going to approve because of the language. The Civil Liberties Union called and told them they were going to fight it on First Amendment issues. The ATF backed off immediately. The ATF is unwilling to pick a fight on the obscenity issue. Maybe for good reason.