5.15.1 IRS Manual - Financial Analysis Handbook (Home). These links will take you to the IRS web site that contains the most recent descriptions of the expense items included and/or excluded from the various expense categories:
220.127.116.11 Allowable Expense Overview;
18.104.22.168 National Standards (Description);
22.214.171.124 Local Standards (Description);
126.96.36.199 Other Expenses (Description).