THE SIGN in the window of the Capitol Hill pharmacy, "Egg Creams, 15 cents," attracted two groups: neighborhood people looking for an inexpensive breakfast and New Yorkers. Today, 13 years later, the sign no longer is in the window, and the price of an egg cream has risen to 45 cents (90 cents for the large size). Nevertheless, New Yorkers continue to come to Grubb's Pharmacy and fountain at the corner of 4th and East Capitol Streets to savor egg creams.

Egg creams, at their simplest, are soft drinks made from chocolate syrup, milk and soda water. To New Yorkers (particularly displaced New Yorkers), the kind of chocolate syrup used and the order in which the ingredients are added and mixed make the difference between an ordinary soda and a perfect egg cream.

Grubb's pharmacist and co-owner Ed Dillon ("the only owner from Brooklyn," he notes) considers those who know that egg creams come in different flavors the "connoisseurs." The "professionals," he adds, can be distinguished from the "non-professionals" by whether they know the "right way" to prepare an egg cream. Dillon's method is to put milk in first, seltzer second, and then stir. By adding chocolate syrup -- Fox's U-Bet for authenticity -- at this point and stirring again, he is able to get a creamy white head on the egg cream.

When he opened the pharmacy in 1967, Dillon says, customers complained about not being able to find New York foods in the Washington area. Many of these foods are now available, but Dillon observes that some things have not changed: "When former New Yorkers discover we serve egg creams, the feeling is still one of old home week, and talk continues to turn to food."

When displaced New Yorkers meet, an instant bond is food: What New York foods have they found locally? What foods did they eat during their last two-day visit to the city? What foods did they bring back?

Among their most revered memories are trips to favorite New York delicatessens for corned beef and pastrami, always lean, on club bread, with knishes and sour pickles on the side; to neighborhood storefront pizzerias for Sicilian pizza by the slice, followed by freshly scooped Italian lemon ices; to the bagel factory for hot salted bagels; to the salumerias for several loaves of Italian bread; and to the bakeries for assorted danish, onion rolls, and rye bread, sliced on the spot, still so warm that they ate the end pieces while walking home.

A large part of the fun -- and seriousness -- is a sense of competition. The following survey was prepared for New Yorkers who salivate at the mention of these foods -- and who have the chutzpa to challenge Ed Dillon's method, contesting that the last step in making perfect egg creams is bouncing additional seltzer off a spoon into the glass to produce the ultimate foamy white head. HOW DO YOU RATE AS A DISPLACED NEW YORKER?

1. Name the most popular brand of soda at a New York deli, listing the three most commonly known flavors.

2. Which is the only commercially available acceptable syrup for egg creams?

3. Name the bakery famous for its blackout cake (also for its chocolate buttercream with sliced almonds on the side).

4. Identify the fast-food chain that sells frankfurters on buttered white toast.

5. Identify the fast-food chain that sells cream cheese on raisin bread.

6. Other than clear, what was the most common color for seltzer bottles?

7. What food is served automatically in a Chinese restaurant in New York, not traditionally served elsewhere in the country?

8. When you bring a pound of butter cookies to people you're visiting, what kind do you buy?

9. What is missing from the following party platter: quartered pineapples, individually sliced, with colored toothpicks?

10. How much did pizza by the slice cost in 1960?

11. What was the name of the cylindrical-shaped ice cream wrapped in paper that you inserted into a T-shaped cone? IDENTIFICATIONS:

12. Appetizing store

13. Frozen custard

14. Calzone

15. One with

16. Heroes

17. Put up water

18. Candy store

19. Charlotte russe SURVEY ANSWERS

1. Dr. Brown's, Black Cherry, Cream, and Cel-Ray

2. Fox's U-Bet (Diamond brand was used in candy stores but was not sold retail)

3. Ebingers

4. Nedick's

5. Chock full o' Nuts

6. Blue, usually delivered to the home once a week on a special seltzer truck. Soda also was available on the truck.

7. Chinese noodles

8. An assortment

9. Maraschino cherries

10. 15 cents

11. Mellorolls IDENTIFICATIONS:

12. A specialty store selling fresh smoked salmon, whitefish and herring; pickles in large barrels; bagels and bialys; cream cheese; bulk halvah; and a variety of candies. When the owners know you, they make a point of going "in the back" to bring out their freshest foods.

13. Soft ice cream. Popularized by Carvel's and best when purchased from the Carvel van that followed the Good Humor truck down your block. The most unusual custard flavors, including banana and pistachio, were available at the custard store located next to Nathan's, Coney Island.

14. A deep fried dumpling made of pizza dough, filled with ricotta and mozzarella cheese and ham, and sold at many New York pizzerias.

15. A kosher frankfurter with mustard and sauerkraut

16. Submarines, hoagies

17. Prepare coffee

18. A small store that seemed to be on almost every street corner, selling packaged candy and, more significantly, pretzel logs in glass jars. Most candy stores had fountains for selling egg creams, lime rickeys, cherry Cokes, malteds, and black and white ice cream sodas. Usually they sold newspapers (set up on a stand outside), magazines, comic books, tobacco products, small toys and Spalding balls.

19. A piece of sponge cake wrapped in a circular piece of white cardboard and topped by whipped cream and a cherry. Years ago, they were available in candy stores.