• Firm (F) - The address matches to a firm record at an address (some firm names exist in the USPS files, associated to an address or a suite number)
• General Delivery (G) - A service in which the USPS hold mail until the addressee collect it; this service is typically used when mail cannot be delivered to a physical location
• High Rise (H) - The address matches to a street address that has secondary units (suite numbers, apartment numbers, etc)
• Military (M) - The address is within a military base; often in this scenario, mail is delivered to a central point on the military base and the mail is further distributed from there
• Post Office Box (P) - Mail is delivered to a box at the Post Office rather than the physical location
• Rural Route (R) - The address is a Rural Route or Highway Contract address (for example, RR1 Box 22 or HC 62 Box 53)
• Street (S) - The address is a street address (for example, 1201 Main St)
• Unknown (N) - The address type is unknown.