Mustard is a "guy thing," I wrote last month. We who have all those muscles (including those in our heads) tend to use mustard to show off.

We ask that it be put not only on the meat of a sandwich, but also on both pieces of bread. Thus, I said, we (somehow) prove our manhood -- even if we spend the next five minutes quenching the fires in our mouths with gallons of root beer.

This all came about because of a roast beef sandwich I ordered recently in Providence, R.I. I asked the counterman to apply "ser-r-r-r-ious mustard" to the meat and to all possible surfaces of all possible bread.

He produced a special vat of dark, dark mustard and laid it on thick. Then he told me that only men request the serious stuff. The last 17 times he has dragged out his special container of mustard, the requester has been male, the counterman said.

I asked readers to weigh in on the mustard-makes-maleness theory. More than 100 did.

First, the feminists, who chewed me in much the same way that I like to chew roast beef begobbed with mustard.

"An Irate Female From Feagaville, Md." said she doesn't like mustard. She loves it.

"And it has to be serious mustard! I don't eat the wimpy mustard! And it has to be on both pieces of bread! And I'm female! So there!"

All this in capitals. Whew!

Rachel Korr, of College Park, said she and other females crave serious mustard because they eat mustard-only sandwiches. It's a way to reduce hip expansion, Rachel writes. And it's fun to "squiggle designs across the bread."

Deborah Smith, of Laurel, says that overmustardization is part of a male tendency to overdo spiciness in general.

"Many of my male friends seem to think that food just isn't `manly' enough for them unless it makes them sweat," Deborah writes. She cites those who add Dave's Insanity hot sauce to salsa and "those incredibly hot Chinese peppers."

Next, the geographically contentious. Anna Havron, of Winchester, Va., was at the head of the line.

"As a woman who spent her culinary formative years in the Southwest, my countertheory is that y'all are East Coast wimps," she says.

"A true, sinus-cleansing roast beef sandwich has ser-r-r-rious mustard on one side (for flavor) and fresh, unadulterated horseradish on the other (for excitement).

"If your nose ain't running, it ain't hot enough."

Meanwhile, Margo Villanova, a recent transplant from Los Angeles, says you haven't turned red in the cheeks until you've tried the mustard at Philippe's, a restaurant on Ord Street. "If you used the top, bottom and meat method [at Philippe's], you would not be able to speak (and maybe breathe) for at least 10 minutes," she says.

Colman's Mustard, made in England, has many adherents on this side of the great sea, to judge from my mail. For those keeping score, the Colman-holics were almost evenly divided by sex -- 44 male, 43 female.

I love Abbott and Costello as much as I love mustard, but it took Howard Goldblatt to clue me to an A&C mustard routine I somehow missed.

Seems Costello declines an offer of mustard for a sandwich. Abbott goes into a wrenching monologue about how the decision will cost a mustard worker his job. Costello finally bursts into tears and slops it on thick. Thanks, Howard, for plugging a gap in my cultural education.

Speaking of culture, Sylvia Fesler, of Northwest Washington, dug out a newspaper clipping that proves mustard's enduring popularity. Seems there's a mustard museum in Madison, Wis. Sorry, no free samples.

Finally, a sign that I may have been right in the first place when I said that hot and spicy is male territory.

Mikele Ann Bryant says she has noticed that Roy Rogers restaurants carry horseradish on their "fixings bars." "Never will you see a woman use it," she reports.

SEND A KID TO CAMP

Do you like free airline tickets? I thought so. One way to qualify for some is to use your credit card to make a pledge to our annual Send a Kid to Camp campaign.

The cards we accept are all tied into the frequent flier programs of the major carriers. If you make a credit card pledge, we get closer to our goal, and you get closer to a grandparent or a vacation. Sounds like a deal to me.

Our goal by July 30: $550,000.

In hand as of July 13: $249,677.02.

TO CONTRIBUTE TO THE CAMPAIGN:

Make a check or money order payable to Send a Kid to Camp and mail it to Bob Levey, The Washington Post, Washington, D.C. 20071.

BY VISA OR MASTERCARD:

Call Post-Haste at 202-334-9000 on a touch-tone phone. Then punch in K-I-D-S, or 5437, and follow instructions.