Reference Materials for tax-advantaged bonds, including tax-exempt, tax credit and direct pay bonds. Publications Tax Exempt Bonds Publications These publications provide a general overview of federal tax law rules that apply to different types of tax advantaged bonds. Tax Exempt Bonds Toolkit Compliance resources for issuers. Volume Cap Limits Current Volume Cap Limits Limits and available amounts Published Volume Cap Limit Tribal Economic Development Bonds Issue Snapshots Tax Exempt Bond Issue Snapshots Issue Snapshots are employee job aids that provide analysis and resources for a given technical tax issue. Visit snapshots for the latest postings. Private Letter Rulings Private Letter Ruling: Basic Concepts Overview description of private letter rulings, including important distinctions between private letter rulings and closing agreements related to tax-advantaged bonds. Revenue Procedure 2021-1 provides formal guidance on the process for requesting private letter rulings.