In most countries, teacher salary is not related to the perceived quality of his or her work. Some, however, have systems to identify the 'best-performing' teachers, and increase their remuneration accordingly. Elsewhere, assessments of teacher performance may be undertaken with a view to identifying teachers' needs for additional training or development, or, in extreme cases, to identify those teachers that should be required to leave the profession. In some countries, teachers are required to re-apply periodically for their license to teach, and in so doing, to prove that they still have the requisite skills. But still there are countries (e.g. Sri Lanka) where teaching cannot be considered as a profession as the teachers are not provided with a license to teach.