Researchers, professionals, teachers and others who are outstanding in their professions sometimes qualify for special treatment under the law. Teachers and professors who teach in educational institutions may be exempt from the H-1B cap. People in this category may also seek to apply for the O-1 visa to avoid the cap on H-1b visas. Some individuals in this category may qualify for a green card without first obtaining an offer of employment. This is referred to as self-petitioning. Of course, individuals in this category may apply for labor certification and other visas available for professionals and/or specialized workers.