MIAMI

Identify yourself as being of "Hispanic, Latino or Spanish origin" on the 2010 U.S. Census questionnaire and you will get to be more specific about your ancestry, such as Mexican-American, Cuban or Puerto Rican.

But check the box for "Black, African-American or Negro" and there will be no place to show whether you trace your identity to the African continent, a Caribbean island or a pre-Civil War plantation.

Some Caribbean-American leaders are urging their communities to write their nationalities on the line under "some other race" on the forms arriving in mailboxes next month, along with checking the racial categories they feel identify them best.

It's another step in the evolution of the Census, which has moved well beyond general categories like "Black" and "White" to allow people to identify themselves as multiracial, and in some cases, by national origin.

The wording of the questions for race and ethnicity changes with almost every Census, making room for the people who say, "I don't see how I fit in exactly," Census Bureau director Robert Groves told reporters in December. "This will always keep changing in this country as it becomes more and more diverse."

In another push tied to the 2010 Census, advocates are urging indigenous immigrants from Mexico and Central America to write in groups such as Maya, Nahua or Mixtec so the Census Bureau can tally them for the first time.

The campaign in the multiethnic Caribbean community reflects a tendency, born from multiple waves of migration, to establish identity first by country, then by race.

"We are completely undercounted because there isn't an accurate way of self-identifying for people from the Caribbean," said Felicia Persaud, chairwoman of CaribID 2010, a New York-based campaign to get a category on the census form for Caribbean-Americans or West Indians.

About 2.4 percent of the U.S. population — more than 6.8 million people — identified on the 2000 Census as belonging to two or more races. A little less than 1 percent of the population — more than 1.8 million people —  wrote in their West Indian ancestry.