Each of the items of appropriation as hereinafter defined and enumerated shall represent, in the broadest permissible sense, a specific purpose, and each such item of appropriation shall be the estimate made and approved for such purpose, subject to encumbrance and expenditure therefor under restrictions otherwise provided by law. The distinctive functional purpose of each shall be that assigned by statute, charter or ordinance to the office, board, commission or department for counties, cities and towns, and to quasi-municipal boards serving a particular function but lacking corporate powers. As applied to each, except where otherwise provided by law, the terms used shall be applied in meaning as follows: the term “personal services” is defined to comprehend all salaries, wages, per diem compensation, fees where the only compensation of the recipient is the fees earned, and all allowances or reimbursement for travel expense where authorized by law and/or defined by law, paid to any officer, deputy, employee or other individual for services rendered or employment in relation to the office, department or subdivision of the municipality, including such items as fees and mileage of witnesses and jurors when paid from the general fund, fees of constables and justices of the peace and all other fees, compensation or remuneration paid to individuals or persons who have only their professional, technical or vocational skills and services to sell. In the departments of roads and highways and/or streets and alleys the term “personal services” shall comprehend all items so defined hereinbefore and shall be further specifically defined to include such items as salaries, wages, per diem compensation and all other compensation or remuneration paid to engineers, surveyors, mechanics, truck drivers, tractor and grader operators, carpenters, etc., for professional, technical and vocational skills and services rendered in relation to employment by or within such department or subdivision of the municipality. The term “maintenance and operation” is defined to comprehend all current expense except those items herein defined as “personal services” and/or “capital outlay,” and “sinking funds,” including all items, articles and materials consumed with use, rentals on machinery and equipment, premiums on surety bonds and insurance, all maintenance and repair accomplished according to the conditions of a contract, and all items of expense paid to any person, firm or corporation who renders service in connection with the repair, sale or trade of articles and commodities. In the departments of roads and highways and/or streets and alleys the term “maintenance and operation” shall comprehend all items so defined hereinbefore, and shall be further specifically defined to include all items, articles and materials consumed with the use in the repair, maintenance, construction or reconstruction of roads, bridges, highways, streets and alleys by the usage of force account labor, rentals on machinery and equipment, premiums on surety bonds and insurance, and all repair and maintenance accomplished under the terms of a contract. The term “capital outlay” is defined to comprehend all items and articles (either new or replacements) not consumed with use but only diminished in value with prolonged use, such as new, or replacements of, machinery, equipment, furniture and fixtures, all real properties, and all construction or reconstruction of buildings, appurtenances and improvements to real properties accomplished according to the conditions of a contract. In the departments of roads and highways and/or streets and alleys the term “capital outlay” shall comprehend all items so defined hereinbefore and shall be further specifically defined to include the cost, and all expense incurred in relation thereto, of rights-of-way or other real property necessary for the construction of roads and highways and/or streets and alleys as the case may be. Provided, that the State Auditor and Inspector may add or substitute, and define, other items of appropriation where necessary to fulfill special functions therein required, but such items shall always be the fewest that will fulfill the requirements of the Constitution or Legislature.