Mass. Gen. Laws ch. 31 § 57
Every year-round temporary position in the labor service of a city where such service is subject to the civil service law and rules shall be deemed to be a permanent position if compensation for service in such temporary position has been paid for a continuous period of two years. Certification to fill such a position shall first be made of persons with experience in such position in the departmental unit. A person employed as a temporary employee in a labor service position for a period of at least two years who receives an appointment as a permanent employee to such position in the same departmental unit shall be deemed to be a tenured employee within the meaning of section thirty-four without serving a probationary period. This paragraph shall take effect upon its acceptance by vote of the city council.
A permanent intermittent junior building custodian in the school department of a city or town who, after the certification of his name on three separate occasions, refuses to accept appointment as a permanent full-time junior building custodian in such school department shall not be eligible for further certification and shall cease to be a permanent intermittent junior building custodian. The appointing authority shall send to the administrator and to such permanent intermittent junior building custodian a notice of termination of the service of such permanent intermittent junior building custodian. Such notice shall set forth the occasion of each refusal and the date of termination of service of such permanent intermittent junior building custodian. This paragraph shall take effect in a city upon its acceptance by vote of its city council, subject to the provisions of its charter, in a town upon its acceptance by vote of the inhabitants of the town at an annual town meeting, or, if such custodians are appointed in a city or town by the school committee thereof, upon its acceptance by such committee.
No person shall be certified by the administrator for appointment to the position of inspector of wires in a city or town unless he has been issued a certificate A or certificate B license pursuant to section three of chapter one hundred and forty-one.
Mass. Gen. Laws ch. 31, § 57