Mass. Gen. Laws ch. 58 § 3
In order to assist the assessors in the performance of their duties, the commissioner shall prepare, issue and periodically revise guides for local assessors. Such guides shall include the rules, regulations, and guidelines of the commissioner relative to the assessment, classification and administration of local taxes, an appraisal manual and, in addition, may include special studies, cost and price schedules, news and reference bulletins and digests of laws relating to local taxation. He shall prepare and issue such other printed instructions to the assessors which are adapted to varying local circumstances and to differences in the character and condition of property subject to local taxation as he shall deem necessary.
He shall conduct or sponsor in-service, pre-entry, and intern training programs on the technical, legal, and administrative aspects of the assessment process and may require assessors to attend such programs. Such programs shall include but not be limited to training required to meet minimum standards of assessment and classification performance established in accordance with section one. The commissioner may contract with educational institutions or appropriate professional associations to provide such training programs. He shall develop, prescribe, and require the use of all forms necessary for administration of the laws relating to the taxation of property. So far as practicable, the forms shall be uniform, but nothing herein shall be deemed to prevent the prescribing of substitute or additional forms where special circumstances require.
He shall annually, on or about January first, furnish to each board of assessors all the information relating to the assessment, classification, valuation and ownership of property taxable in their town that has come into possession of his department, particularly under chapter sixty-five and sixty-five C.
He shall cause a representative of his office to visit every city or town to give to the assessors such assistance as may be authorized or required by law.
Mass. Gen. Laws ch. 58, § 3