Customers at the Dunkin' Donuts on Fisherville Road have a new rule to abide. On the wall behind the cash registers -above the bagels, fritters and holes - sits a new sign: "Please have identification ready. You may be asked to present it."

No, you don't have to show your driver's license to buy a cup of coffee, though obliging customers have been whipping out identification left and right. The rule only applies to credit-card users, said Nicole Nilges, the store's assistant manager. "Kids were taking their parents'credit card and using it, and then their parents were getting the bill, and saying, 'I never went to Dunkin's Donuts,'"Nilges said. Now, when employees can't read the signature on the back of a credit card, they ask for identification.

The sign's been up for about one month, and it may grace other Dunkin' Donuts throughout the city, Nilges said. Embarrassed by that photo on your license? Write clearly or pay in cash.

SARAH LIEBOWITZ