An expense is reported on the operating income statement. It’s a cost necessary to earn revenue during a fiscal-year. For example, the cost of electricity every fiscal-year is considered to be an expense.
A reserve fund expenditure is a disbursement for an asset reported in the reserve fund statement. Expenditures are typically less than yearly reduction in liability through major repairs or replacements. Expenditures are reported in the fiscal-year they occur on the reserve fund statement.