Montana Schools Group Workers Compensation Risk Retention Program v. Dep't of Labor and Industry Employment Relations Division [06/16/95] 1995 MTWCC 48 The assessment methodology used by the Department of Labor and Industry in 1992 and 1993 under section 39-71-201, MCA, amounted to a de facto rule which, pursuant to section 2-4-102(11)(a), MCA, is deemed void for the Department’s failure to follow rulemaking procedures.