458.1 Introduction. This Part contains the definitions (where necessary) of the natural classifications of expense which, as indicated in section 453.2(c) of this Article are a mandated reporting level for expenses. Also contained in this Part are two indexes: one for salaries and wages, by job title; the other, a supplies and materials classification index. The indexes present guidelines for classifying wages and salaries by specific job titles and for proper classification of supplies and services expense.