The document is a booklet from the New Hampshire Department of Revenue Administration containing tax forms and instructions for proprietorships filing the Business Enterprise Tax (BET) and Business Profits Tax (BPT) returns. It provides information on filing thresholds, tax rates, extensions, payments, and common errors. Key details include the 8.5% BPT rate and 0.75% BET rate for tax years ending on or after July 1, 2001, the $150,000 BET and $50,000 BPT gross receipts thresholds, and how to request forms or assistance.