Inadmissibility and Waivers
The legal concept of "inadmissibility" may have been clearer a decade or two ago, when it was referred to as "excludability" -- that is, a set of grounds under which a person could be excluded from the United States. Various grounds of inadmissibility may be applied when a foreign national seeks a temporary (nonimmigrant) visa, permanent residence (a green card), or some other immigration benefit. It's a big issue for many immigrants who, despite being eligible for a visa or green card in every other way, are denied because they are inadmissible on health, financial, security, criminal, or related grounds. In a few situations, however, the applicant can get around the issue by applying for a "waiver," or legal forgiveness.