The fire department was having a busy day. First it was the “two-alarm” fire and then came the “six-alarm” one. The reporter knew there was time and space for only one story, and chose to cover the “six-alarm” fire. After all, as the commercial says, “more flags, more fun.”

Except that the “six-alarm” blaze was a grass fire, burning some garbage and only scorching a couple of houses, one of them abandoned. The “two-alarm” fire, however, gutted a historic church. The reporter may not have known that just from checking the fire department logs.

Journalists often include the number of alarms when reporting fires; in some places, it’s as much a requirement as reporting a cause or damages. But what do those alarms mean? And, more important, do readers understand what they mean, beyond the basic “bigger is bigger”?

The alarm system varies in each jurisdiction; few are strictly “one alarm, two alarm …” progressions. The Chicago Fire Department, for example, starts with “a still alarm,” where two “engines,” two “trucks,” and a battalion chief respond, and then, depending on circumstances, goes to a “high-rise still alarm,” a “still and box alarm,” or a “box alarm,” each with different staffing levels. Then come the “extra alarms,” “2-11,” “3-11,” and so forth. In New York the system is much more complicated, as most things are, but suffice it to say the higher levels are things like “10-75,” “2-2,” “10-60,” and so on. A first alarm in New York calls for two “engines,” two “ladders,” and a battalion chief. New Orleans keeps it simpler, but between “one alarm” and “two alarms” are “complete” and “extra” alarms. (The response to a “first alarm,” for a reported structural fire, involves a district chief, three “engines,” one “ladder,” and a “squad.”)

In many ways, as response levels have become more sophisticated, citing the number of alarms has become a journalistic cliché. Yet many fire departments still categorize fires by the number of alarms—usually for the benefit of the public, not for themselves. Reporters always ask for them, several fire department public information officials said. Yet how many reporters—and readers—can relate that information to the results of the fire? After all, “there can still be death or injuries in a one-alarm fire,” said a public affairs officer for the New Orleans Fire Department.

A more meaningful statistic would be the number of firefighters needed to battle the blaze, in addition to the damages, injuries, cause, and other “requirements” for fire stories. Even a listing of the equipment used might not resonate with readers who don’t know the difference between an “engine” and a “truck.”

But news reports are filled with alarm numbers. “Two houses in Lawrence were damaged by a two-alarm fire yesterday that killed two cats and caused $250,000 damages,” one article said. A quarter-million dollars in damages and two dead cats, yet “only” two alarms? That should ring some bells.

Merrill Perlman managed copy desks across the newsroom at The New York Times, where she worked for 25 years.