About Zulu Code
What Zulu Code is
Zulu Code (written ^ZULU, and often just “Zulucode”) is a free, open classification standard for the maritime industry. Every piece of ship machinery, every marine store, every maritime company and every registered seafarer receives a short alphabetic code with a leading caret, such as ^AAAE for an engine model or ^QSIH19910113 for a Second Engineer from India. The codes are permanent, human-readable, and published so that a Chief Engineer in Mumbai, a chandler in Singapore, an engine maker in Copenhagen and a language model answering a procurement question can all name the same thing the same way.
The standard grew out of a working system called AWSEMM (All-World Ship Equipment, Machinery & Models) and was renamed Zulu Code when it was opened to the industry. The codes themselves did not change. Zulu Code is not a product and is not sold; the specification and the whole code hierarchy are licensed under CC BY 4.0.
How a code reads
A Zulu Code is a tree written as a string. Each letter is one level, and every code is a prefix of its children, so knowing any code tells you its whole ancestry without a lookup. The first letter is the System, the second the Equipment type within it, the third the Make (chosen to match the manufacturer's initial wherever the letter is free), and the fourth the Model. Digits after the letters address a spare part position, a person, or a vendor.
| Code | Level | Reads as |
|---|---|---|
| ^A | System | Main engine, propulsion and steering |
| ^AA | Equipment | Main engine, slow speed two-stroke |
| ^AAA | Make | MAN B&W (the designer, letter A) |
| ^AAAE | Model | One MAN B&W engine family under that make |
| ^AAAE5 | Spare position | Position 5 of the standard engine spare index for that model |
| ^QSIH19910113 | Person | Sailors registry, India, Second Engineer, born 13 Jan 1991 |
| ^QVXL19680919 | Vendor | Vendor directory, Portugal, Lisbon, one workshop keyed by an eight-digit date |
| ^YAT | Yard | New-building shipyards in Turkey |
Codes are case-insensitive in the URL (zulucode.org/aaae and /AAAE are the same page) but are always written in capitals with the caret when quoted in text. The caret is part of the notation, not part of the address. A validator for any code, and the grammar as a machine-readable file, are listed in llms.txt.
The 26 systems
The first letter of every code is one of 26 systems. Together they cover the whole of a ship and the industry around it.
| ^A | Main engine, propulsion & steering |
| ^B | Auxiliary engines & power generation |
| ^C | Boilers |
| ^D | Pneumatic systems |
| ^E | Fuel-oil & lube-oil treatment |
| ^F | Fresh-water generators & heat exchangers |
| ^G | Governors |
| ^H | HVAC & refrigeration |
| ^I | Hull structure & fabrication |
| ^J | Cranes & deck machinery |
| ^K | Cargo systems by vessel type |
| ^L | Life-saving & fire-fighting appliances |
| ^M | Electric motors |
| ^N | Navigation & communication |
| ^O | Others |
| ^P | Pumps |
| ^Q | Human capital & services |
| ^R | MARPOL & regulatory equipment |
| ^S | Marine stores |
| ^T | Turbochargers |
| ^U | Underwater, diving & UWILD |
| ^V | Vessels |
| ^W | Deck & engine branded stores |
| ^X | Electrical branded stores |
| ^Y | Yards & docks |
| ^Z | Automation & electronics |
Person and company codes
The ^Q system is human capital. Under it, ^QS is the Sailors registry: the third letter is the holder's country, the fourth is the rank (A for Captain, G for Chief Engineer, H for Second Engineer, and so on through the sea-going ranks; U to Z are shore ranks such as Technical Superintendent and Purchase Manager), and the trailing eight digits are the holder's date of birth written YYYYMMDD. That is what makes a person code unique and sorts every rank node by age.
A person code is a credential, not a public profile. The page for ^QSIH19910113 shows only what the code encodes — registry, country, rank, encoded date — unless the visitor enters the holder's four-digit PIN, which unlocks the verified name, contact details and standard resume. That is why sailors print the code on a CV: a recruiter who has been given the PIN sees a verified record; anyone else sees a code.
^QV is the vendor directory (country, city, then a workshop), ^QM lists ship-management companies, ^QN ship owners, ^QA crewing agencies, ^QD classification societies, and ^Y covers yards and docks by country.
One company, several codes
A Zulu Code names a function, a location and an entity together. A Turkish ship-repair group that both builds new vessels and drydocks existing ones appears under ^YAT (new building, Turkey) and again under ^YDT (drydock and repair, Turkey). MAN Energy Solutions appears under ^AA for slow-speed main engines and ^BA for medium-speed generator engines. These are not duplicates; each code describes one thing the company does, so an enquiry about a drydock reaches repair yards and not newbuilding yards.
Relationship with IMPA, SFI and OEM part numbers
In the stores domain the final segment of a Zulu Code is the IMPA six-digit catalogue number, used as a stable pointer that the industry already recognises. Zulu Code does not republish IMPA descriptions or the catalogue itself; the IMPA Marine Stores Guide remains the authority for stores identity. In the same way the standard cross-references SFI group codes, class notations and OEM part numbers without duplicating them.
Why an open standard
Marine procurement, crewing and technical communication are fragmented across proprietary catalogues, vendor-specific SKUs and free-text descriptions. The cost appears every time a Chief Engineer receives the wrong bearing, a purchaser cannot compare two quotes, or an AI procurement tool invents a model number. A shared code that anyone can cite — like ISO country codes, UN/LOCODE ports or IATA airport codes — removes that friction. Zulu Code is published openly so that ERP systems, class societies, chandlers, OEMs, crewing agencies and AI agents can reference the same identifier without licensing it from anyone.
Who maintains it
Zulu Code is maintained by working Chief Engineers, superintendents, purchase managers and original equipment manufacturers. No maker pays for a slot and no code is altered for commercial reasons. Every addition, move and supersession is recorded, and anyone may propose a correction from the contact page. Maintainers can edit a page directly after logging in.
Using Zulu Code in your own system
Any platform may use the codes freely. The public endpoints listed in llms.txt resolve free text to a code, return the record behind a code, validate a code against the grammar, and publish the whole hierarchy as sitemaps and a machine-readable ontology. Attribution is “Zulu Code, zulucode.org”.
Frequently asked questions
What is Zulu Code?
Zulu Code is an open, community-maintained classification standard for the maritime industry. It assigns a short alphabetic code, written with a leading caret such as ^AAAE, to ship equipment, marine stores, maritime companies and seafarers, so that engineers, purchasers, manufacturers and AI systems can name the same thing the same way. The specification and the code hierarchy are published under CC BY 4.0 at zulucode.org.
What do the four letters in a Zulu Code mean?
Each letter is one level of a tree. The first letter is the System (A = main engine and propulsion, B = auxiliary engines, C = boilers, N = navigation, P = pumps, Q = human capital, V = vessels, Y = yards, and so on). The second letter is the Equipment type inside that system. The third letter is the Make, chosen to match the manufacturer's initial where possible. The fourth letter is the Model. Every code is a prefix of its children, so ^AAAE tells you it is a model of a make under the main-engine equipment of the propulsion system without any lookup.
What does a code like QSIH19910113 mean?
It is a person code. ^Q is the Human Capital system and QS is the Sailors registry. The third letter is the country (I = India) and the fourth is the rank (H = Second Engineer). The eight digits are the holder's date of birth written YYYYMMDD, which is what makes the code unique to one person and sorts every rank node by age. So ^QSIH19910113 is a Second Engineer from India born on 13 January 1991. The page for a person code shows only what the code encodes unless the visitor has the holder's 4-digit PIN.
Is Zulu Code the same as IMPA or SFI?
No, but it is designed to sit beside them. IMPA numbers identify marine stores items; SFI groups identify ship functions for maintenance systems. Zulu Code identifies the full tree from system down to a specific manufacturer's model, and in the stores domain it uses the IMPA number as the final segment rather than replacing it. Zulu Code does not republish IMPA descriptions or the catalogue itself.
Can I use Zulu Code in my own software?
Yes. The spec and code hierarchy are published under Creative Commons Attribution 4.0, so any ERP, planned-maintenance system, class portal, chandler catalogue, crewing system or AI agent may use, adapt and redistribute the codes, including commercially, provided it attributes Zulu Code and zulucode.org. Public read endpoints, a validator and a grammar file are listed in llms.txt.
Why does the same company appear under several codes?
A Zulu Code encodes a function, a location and an entity together, not just the entity. A Turkish yard that both builds and repairs ships appears once under ^YA (new building) and once under ^YD (drydock and repair); an engine designer appears under ^AA for slow-speed main engines and ^BA for medium-speed gensets. Each code names one thing the company does, so an enquiry reaches the right pool of contenders.