Employers may adopt a range of unethical practices ranging from explicit or implicit discrimination against job applicants, exploitative hiring policies, misleading employees as to the nature of work required or the conditions of work, and biased employee evaluations with a view to career advancement. Personnel may be hired illegally, as with the employment of minors or illegal immigrants. Hiring and promotion may be done on the basis of nepotism or in return for favours (whether sexual or otherwise). The form of salary payment may arranged to ensure tax avoidance or tax evasion.