THE A IN THE WINDOW COMES FROM ONE INSPECTION AND CARRIES NO DATE

There is a card taped inside the window of nearly every restaurant in this city, and most New Yorkers have made a decision based on it without ever learning what it means. The Health Department has been issuing letter grades since July 2010. They are posted at roughly twenty nine thousand restaurants. They are, by volume, the most consulted piece of food safety information in New York.

The grading is arithmetic, not judgment. Inspectors assign deficiency points to each violation they find, weighted by severity. Under fourteen points earns an A. Fourteen to twenty seven earns a B. Twenty eight or more earns a C.

The violations fall into three tiers. Public health violations carry an immediate threat and can shut a room the same day. Critical violations are the ones nobody wants to visualise, live pests and food held outside safe temperature. General violations are everything else, from record keeping to equipment. A restaurant can reach a B on an accumulation of general violations without a single thing in the kitchen that would have made you sick.

Here is the part that changes how you should read the card.

The grade reflects an inspection cycle, and how often a restaurant enters a new cycle depends on how it scored in the last one. Restaurants that score well on the initial inspection are inspected less often than restaurants that score badly. That is a sensible way to allocate limited inspectors and it means the A in the window may be describing a morning many months in the past.

The card does not carry that date. Two rooms on the same block can both show an A, one from last month and one from three seasons ago, and the glass gives you no way to tell them apart.

The other card people misread is grade pending. When a restaurant scores fourteen points or more on an initial inspection, it does not get a B. It gets a re-inspection, no sooner than seven days later, and posts grade pending in the meantime.

So grade pending is not a C by another name and it is not a clean bill either. It is a room that scored poorly once and has not yet been rechecked. Some of those rooms come back with an A. All restaurants are required to post their final grade once it lands, whatever it turns out to be.

None of this is hidden. The Health Department publishes every inspection, every violation cited, every score and every date, searchable by restaurant, before you decide where to eat.

That record answers the questions the card cannot. When was this graded. What was actually cited. Was it a paperwork issue or was it mice. Has the same violation come back three cycles in a row, which is the single most useful signal in the whole system and one the letter grade cannot express.

The grading program did what it was designed to do. Restaurants improved their practices once the public could see the result, which is the entire theory of the thing. The letter is a good headline. It was never meant to be the whole story, and the story is free and sitting one search away.