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Tracking Number Data Wiki

Reference documents with data supporting the detection logic

USPS

Publication 199 — IMpb Implementation Guide (v35, July 2026) — PostalPro Every current USPS package barcode. Appendix J Table 1 has the twenty constructs and their field widths, Table 2 the channel application identifiers. → USPS IMpb C, USPS IMpb N

Publication 91 — Confirmation Services Technical Guide (2004) The pre-IMpb barcode. Service type code, DUNS number, package ID. MOD 10 worked by hand on p35, service type codes on p68. → USPS 20, USPS Legacy, MOD 10

Publication 109 — Extra Services Technical Guide

Publication 97 — Priority Mail Express Manifesting (2017)

J-8 — MOD 10 Check Character Calculations → MOD 10

J-9 — MOD 11 Check Character Calculation

FedEx

Ground Barcode Guide, Ground Label Layout Specification → Ground, Ground 96, Ground GSN, Ground SSCC-18

Express Thermal Label → Express 12, Express 34, ASTRA 32

Service Guide 2022

SmartPost FAQs SmartPost numbers are plain IMpb barcodes with nothing identifying FedEx, so there is no SmartPost format. → USPS IMpb C

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