By the end of the day on Wednesday, some restaurants will have a large letter in their window. This is the debut of a new system designed by city officials to rate the cleanliness of the city’s 24,000+ restaurants. The ratings will be either an A, B or C based on their cleanliness factor. The city’s 157 inspectors will be using wireless hand-held computers that will calculate the score.

Also starting Wednesday the city will offer a website where diners can go and see the rating of any restaurant in the city. The website can be found at www.nyc.gov/health/restaurants.

The new inspection rules will require restaurant owners to post placards displaying their A, B or C ratings. The placards are required to be posted on a front window, door or exterior wall within five feet of the main entrance and must be four to six feet high.