The government definitions applied to these issues have changed over the decades in the United States. Self-designation under each set of definitions (last revised in 1997) is changing too. Americans are becoming less and less race-conscious in self-identification. I have been looking up links on this subject since a few years ago for online discussion of college admission issues in the United States.

College reporting to the federal government is based on the U.S. Census bureau definitions for ethnicity and race categories, which in turn are based on regulations from the Office of Management and Budget, which were announced on 30 October 1997

http://www.whitehouse.gov/omb/fedreg/ombdir15.html

to take effect no later than 1 January 2003 for data collection by all federal agencies.

The Department of Education has more recently updated its guidance to colleges on how to ask ethnicity and race questions

http://www.ed.gov/legislation/FedRegister/other/2007-4/10190...

or

http://www.ed.gov/legislation/FedRegister/other/2007-4/10190...

and has requested colleges change their forms by the high school class of 2010 application year to ask a two-part question, first inquiring about Hispanic ethnicity and then about race, for each student. The student will still be free to decline to answer either part of the question.

"Unlike elementary and secondary institutions, generally, postsecondary institutions and Rehabilitation Services Administration (RSA) grantees use self-identification only and do not use observer identification. As discussed elsewhere in this notice, postsecondary institutions and RSA grantees will also be permitted to continue to include a 'race and ethnicity unknown' category when reporting data to the Department. This category is being continued in the Integrated Postsecondary Education Data System (IPEDS) because the National Center for Education Statistics’ experience has shown that (1) a substantial number of college students have refused to identify a race and (2) there is often not a convenient mechanism for college administrators to use observer identification."

You can look up the detailed category definitions on the website of the United States Bureau of the Census. As the Census Bureau itself notes,

"The concept of race as used by the Census Bureau reflects self-identification by people according to the race or races with which they most closely identify. These categories are sociopolitical constructs and should not be interpreted as being scientific or anthropological in nature."

http://quickfacts.census.gov/qfd/meta/long_68176.htm

"White. A person having origins in any of the original peoples of Europe, the Middle East, or North Africa. It includes people who indicate their race as 'White' or report entries such as Irish, German, Italian, Lebanese, Near Easterner, Arab, or Polish.

"Black or African American. A person having origins in any of the Black racial groups of Africa. It includes people who indicate their race as 'Black, African Am., or Negro,' or provide written entries such as African American, Afro American, Kenyan, Nigerian, or Haitian.

"American Indian and Alaska Native. A person having origins in any of the original peoples of North and South America (including Central America) and who maintain tribal affiliation or community attachment.

"Asian. A person having origins in any of the original peoples of the Far East, Southeast Asia, or the Indian subcontinent including, for example, Cambodia, China, India, Japan, Korea, Malaysia, Pakistan, the Philippine Islands, Thailand, and Vietnam. It includes 'Asian Indian,' 'Chinese,' 'Filipino,' 'Korean,' 'Japanese,' 'Vietnamese,' and 'Other Asian.'

Native Hawaiian and Other Pacific Islander. A person having origins in any of the original peoples of Hawaii, Guam, Samoa, or other Pacific Islands. It includes people who indicate their race as 'Native Hawaiian,' 'Guamanian or Chamorro,' 'Samoan,' and 'Other Pacific Islander.'

. . . .

. . . .

. . . .

The concept of race is separate from the concept of Hispanic origin."

http://quickfacts.census.gov/qfd/meta/long_68188.htm

"Hispanics or Latinos are those people who classified themselves in one of the specific Spanish, Hispanic, or Latino categories listed on the Census 2000 questionnaire--'Mexican, Mexican Am., Chicano,' 'Puerto Rican', or 'Cuban'--as well as those who indicate that they are 'other Spanish/Hispanic/Latino.' Persons who indicated that they are 'other Spanish/Hispanic/Latino' include those whose origins are from Spain, the Spanish-speaking countries of Central or South America, the Dominican Republic or people identifying themselves generally as Spanish, Spanish-American, Hispanic, Hispano, Latino, and so on.

"Origin can be viewed as the heritage, nationality group, lineage, or country of birth of the person or the person's parents or ancestors before their arrival in the United States.

"People who identify their origin as Spanish, Hispanic, or Latino may be of any race."

The federal Department of Education National Center for Education Statistics (NCES) has posted guidance to colleges about how they are to ask about student ethnicity and race according to the federally defined categories.

http://nces.ed.gov/statprog/2002/std1_5.asp

The instructions on the National Center for Education Statistics website provide details on how word ethnicity and race questionnaires and how colleges should report the various categories self-reported by students to the federal government.

See the National Center for Education Statistics Race/Ethnicity FAQ

http://surveys.nces.ed.gov/ipeds/visFaq_re.aspx

and the Association for Institutional Research Race/Ethnicity Information webpage

http://www.airweb.org/page.asp?page=1500

and its subpages for more information about the current of colleges as they implement the new federal regulations for high school class of 2010 applicants to college.

Students of higher education (and applicants to schools of postsecondary education) are treated as adults, and are explicitly permitted to decline to identify their ethnic or racial category.

Note that the decennial census in the United States redefines "race" categories from time to time,

http://www.time.com/time/nation/article/0,8599,1955923,00.ht...

and there is no consistency between the practice of the United States and that of any other country in this regard.

I find it interesting that more and more college applicants are declining to self-report their ethnicity to colleges,

http://www.insidehighered.com/news/2005/02/15/race2_15

an issue explored by the linked article from several points of view. Declining to self-report is everyone's right under law and something that someone of any ethnic self-identification might choose to do. People can decide this issue for themselves, but I like to emphasize in my own life, as a member of a "biracial" family, the common humanity my children, my wife, and I share with all our neighbors and compatriots. We prefer the category label "human" but accept the category label "postracial" in our household.

The latest version of the Minorities in Higher Education Report

http://www.acenet.edu/AM/Template.cfm?Section=CAREE&Temp...

has a lot of detailed numbers (all based on reports colleges make to the federal government) about the growth in college enrollment in all the reported ethnic categories, and the growth of the reported category "race/ethnicity unknown." The "race/ethnicity unknown" category has been the fastest-growing category by far in the reported years.