On Friday, in an otherwise perceptive and appropriate Post story about racial and ethnic identity and its role in the Trayvon Martin shooting death in Florida, two things rankled readers, and me too.

The first sour note was in the lead sentence: “The shooter was once a Catholic altar boy — with a surname that could have been Jewish.”

Seven readers wrote to me, and a couple more phoned in — both Jewish and non-Jewish — to say that this was an unfortunate inclusion in the lead, or at least an unfortunate wording.

Yes, can Zimmerman be a Jewish surname? Sure, but it’s just as likely, perhaps more likely, to be a German Christian surname. And it could be nothing at all, signifying nothing about religious or ethnic background.

The Washington Nationals, for example, have two players on their roster with that last name, Ryan Zimmerman, the third baseman, and Jordan Zimmermann, the pitcher. What is their ethnic or religious background? I don’t know. But I doubt that we can assume much from their surnames.

And in a story carrying the subtext that people in 21st-century America shouldn’t assume much of anything from a name or a label, such as Hispanic, it seemed to me a jarring note.

Here’s what one reader wrote:

“I thought the article about the pan-racial nature of the Florida shooter, George Zimmerman, should not have said that his name ‘sounds Jewish.’ If you think that’s not so bad, here are some suggested leads:

President Barack Hussein Obama, whose name sounds Muslim although he isn’t….

Speaker Newt Gingrich, whose name sounds like he stole Christmas, although he didn’t…

Gov. Mitt Romney, whose name sounds Gentile although he wouldn’t consider it such….”

A Washington D.C. reader added this: 

“The speculative nature of Zimmerman’s surname as ‘could have been Jewish’ was highly inappropriate. Forget that it might have also simply been of German origin; the reference was not a reported fact (as was his mother’s roots, which is a legitimate fact) and is never mentioned again in the article. It smacks of anti-Semitism. . . . I understand the article’s point about the racially charged complexity of this tragedy, but the Jewish reference should never have been used.”

I don’t think that Manuel Roig-Franzia, the lead writer on the story, meant that reference in any way anti-Semitic. As he said in an e-mail to me, “This was a piece on the complexities of perceptions and misperceptions about race, ethnicity, and identity. It’s undeniable that a lot of people around America looked at George Zimmerman’s name and thought he might be Jewish, or wondered if he was.”

Indeed, as Roig-Franzia pointed out, lots of blogs and Web sites were making just such a speculation about George Zimmerman in the wake of the shooting.

But for my money, it would have been a bit smarter to frame the lead this way, and still get across the point about stereotypes.

“The shooter was once a Catholic altar boy — with a surname that many people assumed — wrongly — was Jewish.”

The other problem with the story that readers mentioned was a bit of sloppy language in the lower part of the story.

“Hispanics make up the nation’s largest ethnic group at more than 13 percent of the population, while African Americans are the largest racial group, with more than 12 percent of the population.”

It probably would have been more accurate to substitute “minority” in that sentence for “group,” both times. Whites or Caucasians — and that’s a fairly unsatisfactory term, too, because of the many different national backgrounds of white Americans — remain the largest U.S. racial group, and depending on your point of view — Italian, Irish, English, Polish, German, Russian whatever — may be the largest ethnic group too.

Anyway, the point of all of this is that, when writing about groups and identity, it’s best to be very careful with assumptions, and with language.