Mass. Gen. Laws ch. 33 § 135
The adjutant general may appoint delegates from the National Guard Association of Massachusetts, Inc. to represent the national guard, army and air, of the commonwealth at the annual conventions of the National Guard Association of the United States. Said adjutant general may also appoint delegates from the Massachusetts National Guard Enlisted Association to attend the annual conventions of the Enlisted Association of the National Guard of the United States. The necessary expenses of the delegates so appointed from the active national guard, army or air, may be paid out of military appropriations; provided, however, that no more than a total of thirty delegates shall be appointed annually to attend said conventions; and provided, further, that at no time shall the total amount of expenses paid to any delegate so appointed exceed the rate determined by the human resources division.
Mass. Gen. Laws ch. 33, § 135