llms.txt
+200 −112
https://postalref.com/llms.txt
− Unofficial. Not affiliated with or endorsed by the United States Postal Service. Each fact on a page cites the USPS document and the row or page it comes from. An agent can also add https://postalref.com/mcp as an MCP server; its tools only read.− - [USPS codes and rules, cited to the page they come from](https://postalref.com/): look up a service type code or a term, decode a tracking number, or ask a question.− - [Guides](https://postalref.com/guides): USPS mailing and shipping in 25 guides, each answering the questions people ask about one subject and linking the product pages that belong to it.− - [Products](https://postalref.com/products): 83 pages on USPS products and services, each saying what the product is and citing the USPS documents it quotes.− - [USPS mail classes](https://postalref.com/guides/mail-classes): USPS mail classes group mail by content, such as First-Class Mail for correspondence and USPS Marketing Mail for circulars and catalogs.− - [USPS extra services](https://postalref.com/guides/extra-services): USPS extra services add proof or protection to mail for a fee: Certified Mail proves delivery, signature services control who signs, and insurance covers loss.− - [Intelligent Mail barcodes on letters, flats and trays](https://postalref.com/guides/intelligent-mail): The Intelligent Mail barcode on a letter or flat encodes up to 31 digits in 65 bars: a 20-digit tracking code and a ZIP Code.− - [Presort: bundles, trays, pallets and labeling lists](https://postalref.com/guides/presort): To earn presort prices, a mailer sorts a bulk mailing by ZIP Code into bundles, trays, sacks and pallets, finest level first.− - [Mailpiece design: size, shape and machinability](https://postalref.com/guides/mailpiece-design): A mailpiece's length, height, thickness and weight make it a letter, a flat or a parcel, USPS's mail processing categories.− - [eDoc: Mail.dat, Mail.XML and postage statements](https://postalref.com/guides/edoc): Mailers describe a mailing to USPS with electronic documentation, or eDoc: an electronic postage statement that may also carry qualification reports and barcode data.− - [Full-Service, Seamless Acceptance and eInduction](https://postalref.com/guides/full-service): Full-Service Intelligent Mail is the USPS automation option that requires unique barcodes on every piece, tray and container and electronic documentation of the mailing.− - [Reply mail: Business Reply Mail and Share Mail](https://postalref.com/guides/reply-mail): A business pays the postage on its customers' replies with Business Reply Mail: USPS collects postage plus a per-piece fee only on the pieces customers actually send back.− - [Saturation mail: EDDM, Marriage Mail and walk sequence](https://postalref.com/guides/saturation-mail): Businesses reach every address on a carrier route with saturation mail, sorted in walk sequence, the order the carrier delivers.− - [Package labels and tracking numbers (IMpb)](https://postalref.com/guides/package-labels): A USPS tracking number joins a channel application identifier, Service Type Code, Mailer ID, serial number and check digit.− - [Paying for packages: manifests, eVS and USPS Ship](https://postalref.com/guides/package-payment): Shippers pay package postage by sending USPS a manifest, an electronic Shipping Services File that lists each package's weight, size and postage.− - [Return labels and return services](https://postalref.com/guides/returns): A business gives its customers prepaid USPS return labels, and the business, not the customer, pays the postage for each package that comes back.− - [Package tracking, scan events and proof of delivery](https://postalref.com/guides/package-tracking): USPS reports where a package is through scan events, which Product Tracking and Reporting stores from acceptance to delivery and the USPS Tracking website shows.− - [USPS APIs and shipping software](https://postalref.com/guides/shipping-apis): The USPS APIs let a business's software verify addresses, price packages, create labels, schedule pickups and track packages.− - [Mailability: hazardous, restricted and perishable items](https://postalref.com/guides/mailability): USPS refuses anything that may kill or injure someone or damage the mail, and accepts some hazardous, restricted and perishable items only under Publication 52's conditions.− - [Address matching: CASS, DPV and USPS address data](https://postalref.com/guides/address-matching): CASS-certified address-matching software standardizes an address and matches it to USPS's ZIP + 4 and City State Products to assign its ZIP + 4 and delivery point codes.− - [Move Update: NCOALink and keeping lists current](https://postalref.com/guides/move-update): The Move Update standard requires mailers claiming commercial First-Class Mail or USPS Marketing Mail prices to update their addresses with a USPS-approved method within 95 days before mailing.− - [Undeliverable mail: forwarding, endorsements and ACS](https://postalref.com/guides/undeliverable-mail): USPS forwards, returns or discards mail that is undeliverable as addressed, depending on its mail class, the mailer's endorsement and any change-of-address order.− - [Mail tracking: IV-MTR, IMb Tracing and Informed Delivery](https://postalref.com/guides/mail-visibility): Mailers track letters, flats and their containers in Informed Visibility Mail Tracking & Reporting, IV-MTR, a free USPS application built on scan data.− - [Business accounts: BCG, CRID and Mailer ID](https://postalref.com/guides/business-accounts): A business opens a USPS business account on the Business Customer Gateway or the Business Portal, which assign it a Customer Registration ID, or CRID, and a Mailer ID.− - [Paying for postage: permits, meters, PC Postage and EPS](https://postalref.com/guides/paying-postage): Businesses pay USPS for postage with stamps, a postage meter or PC Postage, or a permit imprint, and the mark on each mailpiece shows which method paid.− - [Mail entry: facilities, drop shipment and appointments](https://postalref.com/guides/mail-entry): Mailers enter business mail at a Business Mail Entry Unit, at a Detached Mail Unit in their plant, or at a facility near its destination.− - [Mail processing: how USPS sorts and moves mail](https://postalref.com/guides/mail-processing): Inside USPS, processing plants sort mail in phases, first toward its destination and then down to a carrier's route, and a carrier delivers it.− - [Mailing promotions and incentives](https://postalref.com/guides/promotions): USPS mailing promotions take a percentage off First-Class Mail and USPS Marketing Mail postage for mailpieces using a technology or print treatment USPS rewards.− - [Getting help from USPS: help desks, centers and councils](https://postalref.com/guides/getting-help): A business mailer reaches USPS through help desks for its online systems, local offices and analysts for its mailings, and a national center for rulings.− - [Address Change Service](https://postalref.com/products/address-change-service): Address Change Service, or ACS, is a USPS post-mailing service that sends mailers change-of-address information and other reasons for non-delivery electronically.− - [Address Element Correction and AEC II](https://postalref.com/products/address-element-correction): Address Element Correction, or AEC, is a computerized address correction process USPS runs for business mailers.− - [Address Information System products](https://postalref.com/products/address-information-system): Address Information System products, or AIS products, are raw USPS database files that help customers standardize addresses, get address details and correct address records.− - [Address Matching System API](https://postalref.com/products/ams-api): The Address Matching System API, or AMS API, is USPS software that developers use to build address matching software.− - [Alternative Designs](https://postalref.com/products/alternative-designs): Alternative Designs is a set of USPS requirements that lets non-rectangular TED-C letters mail at automation letter prices.− - [Ancillary Service Endorsements](https://postalref.com/products/ancillary-service-endorsement): An ancillary service endorsement is a printed instruction on a mailpiece that tells USPS how to handle it when it is undeliverable as addressed.− - [ANKLink](https://postalref.com/products/anklink): ANKLink is an option to the 18-month NCOALink product that tells a mailer a customer moved 19 to 48 months ago, without giving the new address.− - [Automated Package Verification (APV) System](https://postalref.com/products/automated-package-verification-apv-system): The Automated Package Verification System, APV, is a USPS system built to capture postage discrepancies.− - [Bulk Parcel Return Service](https://postalref.com/products/bulk-parcel-return-service): Bulk Parcel Return Service, or BPRS, is a USPS service that returns a high-volume mailer's machinable USPS Marketing Mail parcels to designated postal facilities.− - [Bulk Proof of Delivery Program](https://postalref.com/products/bulk-proof-of-delivery-program): The Bulk Proof of Delivery Program is a USPS program that gives mailers signature proof of delivery records for their mailpieces without a request for each one.− - [Business Customer Gateway](https://postalref.com/products/business-customer-gateway): The Business Customer Gateway is USPS's single entry point for its online business services.+ Unofficial. Not affiliated with or endorsed by the United States Postal Service. Each fact on a page cites the USPS document and the row or page it comes from. Each page below is Markdown, at the page's address with .md added. https://postalref.com/llms-full.txt holds every page in one file. An agent can also add https://postalref.com/mcp as an MCP server; its tools only read. The skill at https://postalref.com/.well-known/agent-skills/postalref/SKILL.md says how to use postalref.+ - [USPS codes and rules, cited to the page they come from](https://postalref.com/index.md): look up a service type code or a term, decode a tracking number, or ask a question.+ - [Index](https://postalref.com/topics.md): Every guide, product page, code table, tracking status and entry postalref holds, each filed under one of ten topics: 3,108 in all.+ - [Guides](https://postalref.com/guides.md): USPS mailing and shipping in 25 guides, each answering the questions people ask about one subject and linking the product pages that belong to it.+ - [Code tables](https://postalref.com/codes.md): 43 USPS code tables, each on one page with every row, cited to the USPS document that prints it.+ - [USPS tracking statuses](https://postalref.com/tracking.md): A USPS tracking status is the line USPS.com shows for a scan of a package, such as Departed USPS Facility, under a category such as In Transit.+ - [Processing at USPS Facility](https://postalref.com/tracking/processing-at-usps-facility.md): Processing at USPS Facility is the tracking status USPS.com shows for 10 scan events in the In Transit category.+ - [Departed USPS Facility](https://postalref.com/tracking/departed-usps-facility.md): Departed USPS Facility is the tracking status USPS.com shows for 4 scan events in the In Transit category.+ - [In Transit, Arriving Late](https://postalref.com/tracking/in-transit-arriving-late.md): In Transit, Arriving Late is the tracking status USPS.com shows for 4 scan events in the In Transit category.+ - [Unpaid postage, item will not be delivered](https://postalref.com/tracking/unpaid-postage-item-will-not-be-delivered.md): Unpaid postage, item will not be delivered is the tracking status USPS.com shows for 3 scan events in the Alert category.+ - [Pre-Shipment, USPS Awaiting Item](https://postalref.com/tracking/pre-shipment-usps-awaiting-item.md): Pre-Shipment, USPS Awaiting Item is the tracking status USPS.com shows for one scan event in the Pre-Shipment category.+ - [Record layouts and messages](https://postalref.com/specs.md): Publication 199's record layouts and Mail.XML's messages, each field as USPS prints it, in the order its file or message holds it.+ - [Tools](https://postalref.com/tools.md): Two tools for USPS tracking numbers: a decoder that names each field, and the check digit worked out one step at a time.+ - [Tracking number decoder](https://postalref.com/tools/tracking-number.md): Paste a USPS tracking number to see what each of its fields means and which checks it passes, each line cited to a USPS document.+ - [Check digit](https://postalref.com/tools/check-digit.md): Type the digits of a USPS tracking number before its check digit to see the check digit worked out one step at a time.+ - [Changes](https://postalref.com/changes.md): Every edition of the USPS code tables on file, newest first, with the codes each one added, removed, retired and changed.+ - [Cases](https://postalref.com/cases.md): Public cases of postage fraud, each told from its court filings and the agencies’ own releases: how the scheme worked, how it came to light and what proved it.+ - [About postalref](https://postalref.com/about.md): postalref reads USPS documents and code tables, and links what it says about USPS to the words it comes from.+ - [USPS mail classes](https://postalref.com/guides/mail-classes.md): USPS mail classes group mail by content, such as First-Class Mail for correspondence and USPS Marketing Mail for circulars and catalogs.+ - [USPS extra services](https://postalref.com/guides/extra-services.md): USPS extra services add proof or protection to mail for a fee: Certified Mail proves delivery, signature services control who signs, and insurance covers loss.+ - [Intelligent Mail barcodes on letters, flats and trays](https://postalref.com/guides/intelligent-mail.md): The Intelligent Mail barcode on a letter or flat encodes up to 31 digits in 65 bars: a 20-digit tracking code and a ZIP Code.+ - [Presort: bundles, trays, pallets and labeling lists](https://postalref.com/guides/presort.md): To earn presort prices, a mailer sorts a bulk mailing by ZIP Code into bundles, trays, sacks and pallets, finest level first.+ - [Mailpiece design: size, shape and machinability](https://postalref.com/guides/mailpiece-design.md): A mailpiece's length, height, thickness and weight make it a letter, a flat or a parcel, USPS's mail processing categories.+ - [eDoc: Mail.dat, Mail.XML and postage statements](https://postalref.com/guides/edoc.md): Mailers describe a mailing to USPS with electronic documentation, or eDoc, an electronic postage statement they send to PostalOne!, the USPS system that records mailing transactions.+ - [Full-Service, Seamless Acceptance and eInduction](https://postalref.com/guides/full-service.md): Full-Service Intelligent Mail is the USPS automation option that requires unique barcodes on every piece, tray and container and electronic documentation of the mailing.+ - [Reply mail: Business Reply Mail and Share Mail](https://postalref.com/guides/reply-mail.md): A business pays the postage on its customers' replies with Business Reply Mail: USPS collects postage plus a per-piece fee only on the pieces customers actually send back.+ - [Saturation mail: EDDM, Marriage Mail and walk sequence](https://postalref.com/guides/saturation-mail.md): Businesses reach most or all of the addresses on a carrier route with saturation mail, sorted in walk sequence, the order the carrier delivers.+ - [Package labels and tracking numbers (IMpb)](https://postalref.com/guides/package-labels.md): A domestic USPS tracking number names the package's channel, service and mailer or retail system, then numbers the piece.+ - [Paying for packages: manifests, eVS and USPS Ship](https://postalref.com/guides/package-payment.md): Shippers pay package postage by sending USPS a manifest, an electronic Shipping Services File that lists each package's weight, size and postage.+ - [Return labels and return services](https://postalref.com/guides/returns.md): A business gives its customers prepaid USPS return labels, and the business, not the customer, pays the postage for each package that comes back.+ - [Package tracking, scan events and proof of delivery](https://postalref.com/guides/package-tracking.md): USPS reports where a package is through scan events, which Product Tracking and Reporting stores from acceptance to delivery and the USPS Tracking website shows.+ - [USPS APIs and shipping software](https://postalref.com/guides/shipping-apis.md): The USPS APIs let a business's software verify addresses, price and label packages, and track them.+ - [Mailability: hazardous, restricted and perishable items](https://postalref.com/guides/mailability.md): USPS refuses anything that may kill or injure someone or damage the mail, and accepts some hazardous, restricted and perishable items only under the conditions of its rulebook, Publication 52.+ - [Address matching: CASS, DPV and USPS address data](https://postalref.com/guides/address-matching.md): CASS-certified address-matching software standardizes an address and matches it to USPS's ZIP + 4 and City State Products to assign its ZIP + 4 and delivery point codes.+ - [Move Update: NCOALink and keeping lists current](https://postalref.com/guides/move-update.md): The Move Update standard requires mailers claiming commercial First-Class Mail or USPS Marketing Mail prices to update their addresses with a USPS-approved method within 95 days before mailing.+ - [Undeliverable mail: forwarding, endorsements and ACS](https://postalref.com/guides/undeliverable-mail.md): USPS forwards, returns or discards mail that is undeliverable as addressed, depending on its mail class, the mailer's endorsement and any change-of-address order.+ - [Mail tracking: IV-MTR, IMb Tracing and Informed Delivery](https://postalref.com/guides/mail-visibility.md): Mailers track letters, flats and their containers in Informed Visibility Mail Tracking & Reporting, IV-MTR, a free USPS application built on scan data.+ - [Business accounts: BCG, CRID and Mailer ID](https://postalref.com/guides/business-accounts.md): A business opens a USPS business account on the Business Customer Gateway or the Business Portal, which assign it a Customer Registration ID, or CRID, and a Mailer ID.+ - [Paying for postage: permits, meters, PC Postage and EPS](https://postalref.com/guides/paying-postage.md): Businesses pay USPS for postage with stamps, a postage meter or PC Postage, or a permit imprint, and the mark on each mailpiece shows which method paid.+ - [Mail entry: facilities, drop shipment and appointments](https://postalref.com/guides/mail-entry.md): Mailers enter business mail at a Business Mail Entry Unit, at a Detached Mail Unit in their plant, or at a facility near its destination.
Showing the first 40 of each.