Some years ago, an 18-year-old from St. Louis named Michael Fay learned the importance of heeding the adage that begins “When in Rome…”. Fay was in Singapore with his mother, where he painted graffiti on cars only to discover it is a serious crime in that island nation. Fay was sentenced to four months in jail, a fine of 3,500 Singapore dollars, and and six strokes of the cane.

You may think that as an adult on your own home turf you have nothing to worry about when it comes to drinking. You’re above the legal drinking age of 18, so what’s there to think about? The answer is provided below in these little-known (to most) New York City laws.

Bringing Your Own Wine to Restaurants with No Liquor License

This one seems like a no-brainer. A restaurant has just opened and hasn’t yet received a liquor license. In the meantime, the management invites patrons to B.T.O. — bring their own. No problem, right?

Wrong. The New York State Liquor Authority (NYSLA) forbids establishments without a license or permit to allow their customers to bring alcohol onto the premises. The restaurant can get into a legal bind, and so can you — the innocent customer.

There is an exception. Restaurants with fewer than 20 seats are exempt from the law.

Drink But Don’t Dance

During his stint as New York City mayor, Rudolph Giuliani re instituted a Jazz Age law that prohibited dancing in nightclubs or bars without a cabaret license. There is an exception. If the number of dancers including you is fewer than three, you’re free to kick up your heels.

In 2003, protesters attempted to have the law repealed via a Million Mambo March, but to this day the law remains on the books.

Taking Wine or Beer on a Picnic

A jug of wine, a loaf of bread — and thou.” The loaf of bread and thou are fine. But if you bring booze to a picnic or other get-together in a public park anywhere in the five boroughs, you are in trouble. The reason: It is illegal to drink alcoholic beverages in public places within city limits, even if you are of legal age.

As of March 2016, police will not arrest offenders in Manhattan, but they can still issue a summons.

That Goes for Cider, Too

But “soft cider,” you say, is non-alcoholic. But since hard cider begins as soft cider, the law doesn’t care.

Cider makers and distributors are lumped together with makers of alcoholic beverages. If the cider you are imbibing at a production of “Shakespeare in the Park” is non-alcoholic, you’re probably safe, but why go through the hassle of having to explain yourself to the gensdarme? Just bring something else to whet your whistle.