Reading a docket number
A reading aid, not legal advice, and not a substitute for the record. Every statement carries a grade — [B] the Board’s own words, [R] the rule or statute, [N] the National Archives’ description of the series, [C] measured from this record, [?] unconfirmed. Nothing here says what any party argued or which side it is on. Figures are counted from the record as it stands.
FD 36873, AB 55 (Sub-No. 785X), EP 711 (Sub-No. 1), NOR 42175, MCF 21155.
- The prefix says what kind of proceeding it is. “Board proceedings are assigned a docket prefix based on the type of case.”[B]
- The number is a sequence within the prefix. The count runs from the ICC era: the record holds Finance Dockets from 1,165 to 36,961 and AB dockets 1 to 1,351.[C]
- A Sub-No. is a proceeding filed under an existing docket — a related transaction, a later phase, or, for the big abandonment dockets, each line a carrier abandons. AB 55 is CSX Transportation’s abandonment docket; its sub-numbers pass 1,000. Sub-numbers are the norm for AB (5,542 of 6,646 in the registry) and common for EP (252 of 449) and FD (1,221 of 8,728); rare elsewhere.[C]
- A suffix letter qualifies the proceeding. X marks an exemption (below).[C]
- Docket Yard folds a docket and its sub-numbers into one sheet, because the Board’s own search treats a sub-docket as risky to find on its own.
The Board’s search form offers 35 prefixes and 20 suffix letters and defines none of them; its tips page defines five.[B] What follows covers all 35.
The five prefixes that carry the living record
Together these hold 26,844 of the registry’s 32,640 dockets and nearly every filing since the watch began.[C] Each has its own page.
| Prefix | What it is | Dockets | Filings held |
|---|---|---|---|
| FD Finance Docket list | Line sales and leases, trackage rights, control and mergers, declaratory orders, constructions | 8,728 | 21,863 |
| AB Abandonment list | Abandonments and discontinuances of service, including trail use | 6,646 | 14,718 |
| NOR Formal complaint list | Complaints, including rate cases, unreasonable-practice cases and the common carrier obligation | 4,292 | 4,048 |
| EP Ex Parte list | Rulemaking and information-gathering proceedings the Board opens itself | 449 | 11,918 |
| MCF Motor carrier finance list | Control and mergers among intercity bus companies | 6,729 | 634 |
Prefixes with a smaller or older record
A few hold a live, small stream today; most of the rest are ICC-era series the Board inherited and keeps searchable. The record column is what the registry holds.[C] A row graded [?] is a reading of the captions that the Board’s records staff have not yet confirmed; it is shown so the gap is public.
| Prefix | Record | What it is |
|---|---|---|
| WB live | 117 125 filings | Waybill data requests. “The Carload Waybill Sample is a stratified sample of carload waybills for U.S. rail traffic”. WB 26 is the current series; each sub-number is one request, answered by a decision under 49 CFR 1244.9, with objections from the railroads whose data it is. Every caption reads “Request for / Release of Waybill Data”. [B][C] |
| RR live | 6 15 filings | Released rates — a carrier’s request to limit its liability for loss or damage in exchange for a lower rate (49 U.S.C. §14706 for motor carriers, §10502 exemptions for rail). Household-goods movers’ released-rates orders live here; the Board “oversees tariff requirements for interstate moving companies” and refers moving disputes to FMCSA. [B][C] |
| SO live | 22 | Service orders — emergency orders directing service when a carrier cannot or will not provide it (49 U.S.C. §11123): “Petition for Emergency Service Order”. [C][R] |
| PTO | 6 | Passenger train operation orders — numbered orders concerning a freight carrier’s handling of passenger trains (the captions name the Indiana Harbor Belt). Statutory basis unconfirmed (49 U.S.C. §24308 governs Amtrak’s use of freight facilities). [C][?] |
| DOP live | 4 | Designated operator certificates — a carrier designated to operate a line another carrier is abandoning, under 49 CFR Part 1150 Subpart B. [R][C] |
| SDM live | 569 39 filings | System diagram maps — each carrier’s mandated map of its lines by category (Category 1 = anticipated abandonment within three years), 49 CFR §1152.10–.13. One docket per carrier. [R][C] |
| CU live | 16 | Paperwork Reduction Act notices — the Board’s 60- and 30-day notices seeking OMB clearance for its information collections. Not proceedings between parties. [C] |
| SUB | 26 | Depreciation rates — “In the matter of prescribing depreciation rates for use in computing depreciation charges” for a named carrier (49 U.S.C. §11143). Suffix letters distinguish successive prescriptions. [C] |
| AM | 3 | Administrative matters of the agency itself: “Senior Executive Service Performance Review Board”, “Implementation of the Regulatory Flexibility Act”. [C] |
| STA | 7 | Special tariff authority for non-contiguous domestic water carriers — permission to change a tariff on short notice. The Board keeps “rate regulation of non-contiguous domestic water transportation”. The expansion of the letters is unconfirmed. [B][C][?] |
| WCC | 5 114 filings | Water carrier complaints in the non-contiguous domestic trade (Hawaii, Alaska, Puerto Rico, Guam): “DHX, Inc. v. Matson Navigation Company”. [B][C] |
| WC | 2 | Water carrier authority, ICC-era: “Champion’s Auto Ferry, Inc. — Algonac, MI”. [C] |
| EPM | 164 | Ex Parte, motor — ICC rulemakings for the trucking industry: “Review of Motor Tariff Regulations — 1993”. Closed series. [C] |
| MC | 178 | Motor carrier operating authority — the ICC’s certificates and permits by carrier docket number (a fraction of the ICC’s ~247,000); the sub-number is the application. Live motor authority is FMCSA’s since 1996. [C][B] |
| MCC | 726 | Motor carrier complaints and declaratory orders: “AAA Cooper Transportation v. Ross Neely Express”. The Board retains a narrow motor-carrier jurisdiction (49 U.S.C. subtitle IV part B). [C] |
| NOM | 1,446 12 filings | Motor carrier rate and practice petitions — overwhelmingly shippers’ petitions for declaratory order on “certain rates and practices” of a trucking company (the 1990s undercharge cases). Closed series. [C] |
| ISM | 1,949 16 filings | Investigation and suspension, motor — ICC proceedings suspending and investigating a proposed motor tariff. Closed. [C][N] |
| IS | 270 7 filings | Investigation and suspension, rail — the same for rail tariffs: “Surcharge on Furniture, Conrail, October 1979”, “Cancellation of Reciprocal Switching”. Closed. [C][N] |
| FSA | 14 | Fourth Section applications — carriers seeking permission to charge more for a shorter haul than a longer one over the same line (the Interstate Commerce Act’s “long-and-short-haul” clause). Closed. [N][C] |
| S5M | 240 281 filings | Section 5a agreements, motor — ICC approval of rate-bureau agreements among motor carriers under §5a of the Interstate Commerce Act (antitrust immunity for collective ratemaking). Closed. The expansion of the letters is unconfirmed. [C][?] |
| SAI | 11 | Shipper agreements — approval of agreements among shippers’ associations: “American Petroleum Institute Agreement”. Statutory basis unconfirmed (49 U.S.C. §10706). [C][?] |
| MXC | 13 | Mexican carrier certificates — ICC-era operating authority for Mexico-domiciled motor carriers. Captions are personal names. Unconfirmed. [C][?] |
| CNO | 1 | Captioned “Classification” — a single ICC-era docket; meaning unconfirmed. [?] |
| ARB, ASC, DSO, RER, S5A, SUS | 0 | Offered by the search form; nothing in the record. Likely: ARB arbitration; S5A Section 5a agreements (rail); SUS suspension; DSO directed service orders; ASC, RER unknown. [B][?] |
Suffixes
The form offers twenty letters; the record uses them unevenly.[B][C]
| Suffix | Where | Meaning |
|---|---|---|
| X | AB (3,370) | Exemption — the sub-docket proceeds by notice or petition for exemption rather than application. Every X caption reads “…Abandonment Exemption…” or “…Discontinuance of Service Exemption…”. [C] |
| TA | MCF (1,388), FD (1) | ICC temporary authority — provisional approval pending a decision (the MCF captions carry the ICC’s “(T1)/(T2)” transaction codes). Meaning unconfirmed. [?] |
| S | NOR (865) | Attached to ICC-era rate complaints of the late 1970s–80s (“…v. Burlington Northern”). Meaning unconfirmed; candidates: suspended, small, or the ICC’s “S” docket sub-series. [?] |
| N | AB (476) | Attached to Conrail’s abandonment sub-dockets (AB 167 is Conrail’s docket) around the 1980s. Meaning unconfirmed; candidate: notice under the then-new class exemption. [?] |
| A, B, C … U | FD, SUB, S5M, EP, SO | Successive related proceedings under one sub-docket — FD 28640 (Sub-No. 9) A–M are the Milwaukee Road reorganisation’s many pieces; SUB 851 C–F are successive depreciation prescriptions; S5M …A are amended agreements. [C] |
| 0 | FD, EP (3) | A literal zero, appearing on a few captions; probably an entry artefact. [?] |
Decision types, as the Board labels them
The Board’s search offers nine;[B] the record holds them in this proportion:[C] Decision (13,762), Notice of Exemption (2,228), Notice (1,918), Environmental Review (1,512), Notice Of Court Action (342), Corrected Notice (47), Corrected Decision (41), Final Decision (9), Policy Statement (9), Notice Of Director's Decision (7), Extension (4), Corrected Environmental Review (3). A Decision is the Board’s or a delegated official’s ruling; a Notice of Exemption a class exemption taking effect on notice; an Environmental Review the Office of Environmental Analysis’s assessment (AB and FD only); a Notice a procedural, hearing or Federal Register notice; a Notice of Court Action a court ruling on a Board decision (every one is on the court-action register); a Corrected decision or notice an errata reissue — Docket Yard records both versions.
Not the Board — where a reader with a rail problem should look
A large share of people who reach the Board are at the wrong agency. From the Board’s own material:[B]
| Concern | Who handles it |
|---|---|
| A train blocking a crossing; crossing signals; horn noise; track and equipment safety; hazardous materials; derailments | The Federal Railroad Administration (safety, 49 U.S.C. chapter 201) and state agencies. The Board hears crossing evidence only inside a merger case. |
| A household-goods mover’s conduct, damage claims, licensing | FMCSA; the Board only “oversees tariff requirements”. |
| Trucking authority, MC numbers, insurance | FMCSA (since 1996). |
| Amtrak on-time performance | The Board, on complaint (49 U.S.C. §24308(f); a NOR docket). |
| Rail rates, car supply, service failures, interchange, a community concern about a railroad’s activities | The Board — start with Rail Customer and Public Assistance, “a free service” whose staff “informally advise disputing parties” but “cannot order a specific resolution”. |
| A pipeline (non-energy) or a water carrier in the domestic offshore trades | The Board. |
| Energy pipelines, ports, ocean shipping | FERC, the FMC. |
Sources (all read 2026-08-26): the Board’s Tips for Searching STB Records (the one page on stb.gov that defines prefixes), About STB, Litigation Alternatives, Need Assistance?, Environmental Overview, Household Goods Tariff Guidance, Legal Resources, Major Railroad Mergers FAQs, press release PR-22-55; 49 CFR §1152.50, §1180.2, Parts 1150 and 1111; NARA records schedules N1-134-99-002 and DAA-0134-2013-0017; the search form’s own prefix and suffix lists. Permanent address docketyard.org/about/prefixes. Something wrong? Corrections.