About Publication 526, Charitable Contributions Information about Publication 526, Charitable Contributions, including recent updates. Publication 526 explains how to claim a deduction for charitable contributions. 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 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.