About Publication 535, Business Expenses Publication 535 discusses common business expenses and explains what is and is not deductible. This publication discusses common business expenses and explains what is and is not deductible. The chapters cover general rules for deducting business expenses and specific expenses. About Publication 538, Accounting Periods and Methods Publication 538 explains some of the rules for accounting periods and accounting methods. It is not intended as a guide to general business and tax accounting rules. About Publication 542, Corporations Publication 542 discusses the general tax laws that apply to ordinary domestic corporations. About Publication 925, Passive Activity and At-Risk Rules Information about Publication 925, Passive Activity and At-Risk Rules, including recent updates and related forms. Publication 925 discusses two sets of rules that may limit the amount of your deductible loss from a trade, business, rental, or other income-producing activity. About Publication 947, Practice Before the IRS and Power of Attorney Publication 947 discusses who can represent a taxpayer before IRS and what forms or documents are used to authorize a representative. Usually, attorneys, CPAs, enrolled agents, and enrolled actuaries can represent taxpayers before IRS. This publication discusses who can represent a taxpayer before the IRS and what forms or documents are used to authorize a representative. About Publication 3402, Taxation of Limited Liability Companies Publication 3402 is used internally by Counsel, walk-in and taxpayer education as well as fed-state. This publication provides federal income, employment, and excise tax information for limited liability companies.