Completion of probation length letter is given via the employer to the employee after he has successfully finished the probation period as consistent with the agreement among the agency and the employee. Probation period is the period of time preceding everlasting employment, where the employee is not a everlasting employee inside the enterprise until he completes a positive probation period and at the quit of the probation period, upon receipt of the probation period letter the employee turns into a everlasting employee of the enterprise.