Waivers are the next topic of study. It's fun because it takes everything I learned so far and flips it on its head. For example, persons are inadmissible for a whole host of reasons, including past immigration and criminal violations. Along come waivers (background cavalry music) to the rescue.
There are specific waivers for specific grounds of inadmissibility, but the general waiver allowing nonimmigrants to enter the U.S. is the 212(d)(3)(A) waiver. Persons who already have travel documents, such as visas, apply when they enter -- at airports, for example. There is no application or fee. Persons who are applying for a visa apply for the waiver on a separate application form which they submit to the U.S. consulate or embassy. The waiver can also be requested if a person is in removal proceedings on an inadmissibility charge.
There are three factors that will be reviewed: whether the applicant poses a risk to the U.S. if she is allowed to enter, the seriousness of the criminal or immigration law violation and the reason for wanting to enter the U.S. In a nutshell, the success of all waivers depends on the applicant's (or her attorney's) ability to document human suffering on paper. Cry me a river.