Alien: An alien can be a beneficiary of a petition filed by a petitioner with U.S. Citizenship and Immigration Services (USCIS) for an immigration benefit or an applicant to USCIS for related benefits. An alien can also be an applicant to a U.S. consulate for a visa.

AFM: American Federation of Musicians

AGVA: American Guild of Variety Artists

CBP: U.S. Customs and Border Protection, part of the Department of Homeland Security

Classification: A nonimmigrant classification or status such as O or P, meaning a particular statutory category that permits an alien temporarily to engage in defined activities in the U.S. in accordance with USCIS regulations as disclosed in the underlying petition.

Consular Section, Consular Post or Consulate: Each U.S. embassy abroad has an independent consular section that is responsible for issuing visas, among other things. Consular posts, or consulates, perform the same functions but are located elsewhere than the Embassy.

CPT: Curricular Practical Training

CSC: California Service Center is one of two U.S. Citizenship and Immigration Services (USCIS) Service Centers processing I-129 and I-539 filings. Petitioners located in the following states should file with CSC:  Alaska, Arizona, California, Colorado, Guam, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, North Dakota, Ohio, Oregon, South Dakota, Utah, Washington, Wisconsin, Wyoming. See our USCIS Service Center Tips for the CSC mailing address and contact information.

DOS: Department of State

DSO: Designated School Official

EAD: Employment Authorization Document, issued by USCIS service centers.

I-797: When USCIS approves a petition or application, it issues an I-797 Notice of Action. The I-797 will state the classification and classification period (length of time) for which USCIS has approved a given classification. USCIS may also issue an I-797 Request for Evidence (RFE) that must be responded to before it will process the application. The I-797 can represent approval for an alien outside the U.S. to acquire a visa (if needed) to enter in a particular classification. It can also represent approval for that alien to remain in the U.S. in that classification beyond the original classification period, in which case it will have a substitute I-94 attached to it affirming an approved extension of stay. And, it can represent USCIS approval for an alien's change from one status to another within the U.S. and for that alien's extension of stay in the new status, in which case it, too, will have a substitute I-94 attached.

I-94: If CBP admits the alien, it generally will issue to the alien a small white card (a green one for visa waiver entries) that states the visa classification and length of time for which the alien is admitted. This is the I-94 card (I-94W in the case of visa waivers). Once the alien is in the U.S., the I-94 is far more important than the visa or the I-797. Even if the I-797 classification period is longer than the departure date on the I-94, the I-94 governs. Even if the visa expires while the alien is in the U.S., the I-94 governs! USCIS inspectors at the port of entry or preflight inspection facility have discretion to ignore the prior grant by USCIS of a petition or by a U.S. consulate of a visa for the classification involved if they suspect error, fraud, or misrepresentation. They must refuse entry unless the alien has a valid passport and an appropriate visa (except for Canadians, waiver cases, and other rare instances).

IATSE: International Alliance of Theatrical Stage Employees

KCC: Kentucky Consular Center, part of the DOS Visa Office to which CIS service centers send their I-129 petition approvals and associated files for scanning and transmission to consular posts.

MRV: Machine-Readable Visa

Nonimmigrant: An alien entering the U.S. temporarily, not intending to remain here permanently. "Nonimmigrant intent" is an important consideration for all aliens seeking O and P status, except for those in O-1B classification and their dependents.

NCSC: NCSC: National Call Service Center (part of USCIS), the toll-free number for most forms of assistance from USCIS, 1-800-375-5283.

Petition: USCIS Form I-129 Petition for Nonimmigrant Worker is used to obtain the O and P work-related nonimmigrant classifications, among others. Occasionally, you may need to use an I-539 Application to Extend/Change Nonimmigrant Status to address the immigration needs of spouses and dependents (unmarried children under age 21) of aliens already in a nonimmigrant status (such as O or P).

Petitioner: The individual, employer, presenter, agent, or other party who files a petition on behalf of an alien for a particular nonimmigrant classification.

PFI: Pre-Flight Inspection facility, where aliens undergo inspection by CBP personnel prior to boarding flights to the U.S.

POE: Port of Entry (air, land or sea)

RFE: Request for Evidence (see definition of I-797 above)

USCIS: U.S. Citizenship and Immigration Services, part of the Department of Homeland Security.

Visa: A physical item entered into a passport that contains a biometric photo embedded with fingerprint data and other information, including the nonimmigrant classification involved. Of itself, a visa does not impart status of any kind; rather, the visa simply is a travel document that enables the alien to present himself/herself at a POE or PFI for admission in a certain status. An alien can apply for entry at any point during the visa's validity. That the visa may expire while the alien is in the U.S. is irrelevant. What matters is the expiration date of the underlying classification period, for it is to that date, not the expiration date of the visa, CBP is supposed to admit the alien. In general, all aliens require visas to enter the U.S. The visa requirement is waived for certain aliens, including those entering in visa waiver program status and Canadian citizens.

VO: Visa Office of the Department of State

VSC: Vermont Service Center is one of two U.S. Citizenship and Immigration Services (USCIS) Service Centers processing I-129 and I-539 filings. Petitioners located in the following states should file with VSC:  Alabama, Arkansas, Connecticut, Delaware, District of Columbia, Florida, Georgia, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Mississippi, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Oklahoma, Pennsylvania, Puerto Rico, Rhode Island, South Carolina, Tennessee, Texas, Vermont, Virginia, U.S. Virgin Islands, West Virginia. See our USCIS Service Center Tips for the VSC mailing address and contact information.

VWP: Visa Waiver Program

Work-related: The category in question permits the alien to work in the U.S. Aliens in the U.S. on B visas or in Visa Waiver Program status cannot work in the U.S., except under very narrow circumstances. If authorized, those in F-1, M-1, and J-1 status may do so for any employer. Aliens in "employer-specific" classifications such as O and P (and H-3 and Q-1) may work only in accordance with the itinerary or activities specified in the petition though, in certain circumstances, they may render similar services not previously disclosed.