Rule 1.5: You can use technical nouns from approved categories

Compliant, and worth knowing why

Retract the main landing gear.

'main landing gear' is an approved technical noun even though 'main' alone is not an approved dictionary word.

Not STE: The display is blacker than before.

STE: (No compliant word-level rewrite exists — restructure to avoid comparing color terms at all, e.g. state the specific color or a measured fact instead of comparing it.)

comparative/superlative color forms are never permitted in STE, including 'more'/'most' constructions; do not propose 'more black' as compliant.

Category 1

Official parts information

Terms that refer to all design items. For example, technical nouns included in illustrated parts catalogs or engineering drawings.

bolt, cable, clip, conductor, contact, engine, ferry tank, filter, hatch, hazard lights, indicator, light, logo, oil seal, prelubricated seal, pipe, propeller, retractor link, screw, switch, transceiver

Category 2

Vehicles or machines, and locations on them

Terms that refer to all types of vehicles and machines, and the locations that are part of these units.

aircraft, aircraft carrier, airframe, airplane, bicycle, cabin, car, cargo compartment, cargo hold, cockpit, deck, engine room, fuselage, helicopter, galley, lifeboat, overhead panel, ship, submarine, tank, train, truck, wing, wing root

Category 3

Tools and support equipment, their parts, and locations on them

Terms that refer to all types of tools, support equipment, their parts, and locations that are part of these items.

access ladder, blade, brush, cap, chock, clamp, cover, display, drill, file, gauge (gage), graduated beaker, handle, jack, label, rigging pin, roller, rope, rung, shaft, stand, tag, test rig, torque wrench, trestle

Category 4

Materials, consumables, and unwanted material

Terms that refer to materials, consumable items, and other substances that can cause contamination or malfunctions.

acid, adhesive, aluminum alloy, ammunition, compound, copper, debris, detergent, dirt, disinfectant, dust, foam, foreign object, fuel, grease, hazardous substances, hazardous waste, metal, metallic coating, oil, paint, penetrant spray, plastic, primer, sealant, sealing, soap, stainless steel, tape, waste, water, wire

Category 5

Facilities, infrastructure, and logistic procedures

Terms that refer to the management, structure, and operations of physical facilities, infrastructure systems, and logistic procedures. For example, areas for utility systems, transportation networks, storage, distribution processes, and operational logistic workflows.

airport, apron, base, building, camp, dock, engine shop floor, flight simulator, gate, handling, hangar, packaging, packing, port, service bay, shipping, shop, store, storage, transport

Category 6

Systems, components and circuits, their functions, configurations, and parts

Terms that refer to the structure, operation, composition, and system design.

air conditioning, amplifying circuit, armament, audio, aural warning system, collapsed position, exhaust, flight management, hardware, inhibiting signal, injection, inlet, input frequency, latch, pedal, power unit, pump, reverse mode, reverse position, standby mode, upright position, vent

Category 7

Mathematical, scientific, engineering terms, and formulas

Terms that refer to concepts, design, calculations, or methodologies.

acceleration, allowance, astronomy, atom, average, biochemistry, biology, biome, burr, capacitance, carbon, category, cavitation, center, circle, coefficient, combination, configuration, conversion, count, critical temperature, curve, cycle, defect, degree, deceleration, density, diameter, displacement, duty cycle, elapsed time, electricity, energy, exponent, failure, ferry flight, flutter, force, fumes, genetics, geology, geophysics, graph, gravity, hardness, heat treatment, idle speed, ignition, inhibition, instrumentation, interference, issue, light, line replaceable unit, load, loss, measurement, modification, momentum, motoring, overhaul, oversized hole, oxygen, performance, phase, polarity, power, pressure, process, radius, rating, ratio, reduction, relative angular position, resistance, scan, shutdown, signal, specific gravity, stall, standard, steam, stiffness, strength, suction, temperature, tension, thread, tightness, torque, toxic property, vapor, voltage, water vapor, “C = (A - B) - 0.063 mm”

Category 8

Navigation and geographic terms

Terms that refer to positions, directions, or locations related to mapping, routing, or spatial orientation.

air, altitude, attitude, axis, bank, clearance, climb, coordinates, critical approach, datum, delay, deviation, drag, east, France, glideslope, gradient, heading, landing, leeway, Lima, north, pitch, roll, skid, south, west

Category 9

Numbers, units of measurement and time (and their symbols)

Terms that refer to quantitative data, measurements, or time-related information.

92, 303, ampere (A), degree, first (1st), half, hour (h), kilogram (kg), knot, liter (L or l), meter (m), mile, minute, month, ohm, one, one-quarter, second, second (s), second (2nd), square inch (sq.in.), spring, third (3rd), three, year, winter, zero

Category 10

Quoted text

Terms that refer to texts that you cannot change in technical writing. For example, texts on placards, labels, signs, markings, and display units.

abort button, EXIT sign, INOP system, OXYGEN pushbutton switch, ON position, NEXT button, FAULT legend, NO STEP marking, FASTEN SAFETY BELT sign, WEAR PROTECTIVE CLOTHING sign

Category 11

Professional roles, individuals, groups, organizations, and geopolitical entities

Terms that refer to professional functions, names of persons, organizations, companies, teams, sovereign states, or entities related to processes, responsibilities, or decision-making.

air traffic control, British Broadcasting Corporation (BBC), captain, commander, copilot, crew, crew chief, European Aviation Safety Agency (EASA), Federal Aviation Administration (FAA), John Kirkman, manufacturer, operator, Transport Canada Civil Aviation (TCCA), United States of America (USA)

Category 12

Parts of the body

Terms that refer to anatomical features or functions related to medical, biological, or ergonomic contexts.

blood, digestive system, ear, eyes, hair, hand, head, lung, mouth, respiratory tract, skin, stomach

Category 13

Common personal effects, food, and beverages

Terms that refer to everyday personal items and types of food and beverage.

beans, bread, cigarette lighter, clothing, coffee, flour, footwear, high-heeled shoes, jewelry, lipstick, matches, milk, mineral water, nail scissors, perfume, pizza, shampoo, wine

Category 14

Medical terms

Terms that refer to medical conditions, procedures, or anatomical structures.

allergy, aspirin, asthma, blood poisoning, breathing, circulation, dermatitis, diabetes, dizziness, female, hallucination, headache, heart rate, irritation, male, medication, nausea, pneumonia, pregnancy, pulse, skin irritation, virus

Category 15

Official documents, parts of documentation, standards, and guidelines

Terms that refer to different types of official documents and their structural parts. For example, manuals, technical records, standards, specifications, and regulations requirements.

Acceptance Test, Activation/Deactivation, Allowable Damage, attention, caution, chapter, Checklist, Class, Cleaning, Compass Correction Card, danger, data module, Description and Operation, diagram, engine logbook, Federal Aviation Regulations, Fault Isolation, figure, flowchart, font, Functional Test, Ice and Rain Protection, Inspection/Check, issue, language policy, letter, maintenance planning, maintenance practice, maintenance records, Normal Braking, note, notice, packaging, page, paragraph, parentheses, post-flight report, post-mod, pre-mod, prerequisite, preservation, reference, Removal/Installation, Required Conditions, Repair Scheme, recommendation, revision, section, Service Bulletin, Standard Practices Manual, storage, Structural Repair Manual, table, test procedure, training material, Transportation, valid welding certificate, warning

Category 16

Environmental and operational conditions

Terms that refer to external factors and operating parameters that are related to systems or processes.

atmosphere, cloud, day, daylight, ice, hail, humidity, lightning, moisture, night, rain, relative humidity, sand, snow, storm, turbulence, volcanic ash, wind

Category 17

Colors

Terms that refer to colors that identify color-related properties, or show color attributes in different contexts. Colors are adjectives, but STE identifies them as technical nouns. Comparative and superlative forms of colors (for example, blacker, the reddest) are not permitted in STE.

beige, black, cyan blue, dark brown, gray, green, magenta, light green, orange, red, white, yellow

Category 18

Damage terms

Terms that refer to types of defects or degradation and give information about malfunctions.

buckle, chafing, corrosion, crack, crack propagation, deformation, dent, discoloration, distortion, erosion, fracture, fraying, galling, kink, nick, score, scratch, stain, spurious fault message

Category 19

Computer science, information and communication technology

Terms that refer to technological concepts, systems, or components in this subject field.

add-in, add-on, AI, arrow, artificial intelligence, authentication, backup, backup file, bookmark, chatbot, content, cursor, cybersecurity, database, deep learning, dialog check box, digitalization, digitization, e-mail, embedding, field, file, firewall, hallucination, HTML, icon, interface, internet, laptop, large language model, local operation, machine learning, memory, menu, metadata, mouse, network, operating system, phone, plug-in, pre-loaded software, preset value, prompt engineering, remote operation, screen, search engine, smartphone, status bar, store, tablet, token, toolbar, touchscreen, tweet, tuning, update, voice mail, XML

Category 20

Civil and military operations

Terms that refer to concepts and activities, service delivery, product management, and customer and life-cycle support in civil and military operations.

armed forces, assault, bomb, bullet, checkpoint, combat plan, contractor, customer, customer support, customer service, deployment, echelon, ejection seat, end item, end user, evacuation, formation, ground zero, gun, Integrated Product Support (IPS), know-how, lifecycle, machine gun, maintenance concept, mission, obsolescence, operator, Original Equipment Manufacturer (OEM), patrol

Category 21

Law and regulations

Terms that refer to legal and regulatory texts. For example, contracts, warranty texts, certificates, standards and specifications, and legal papers.

action, ambiguity, appeal, arbitration, bankruptcy, communication, competence, compliance, concession, contract, court, damages, explanation, explanatory text, impeachment, jury, law, judgement, jurisdiction, purpose, recommendation, scope, serious incident, serious offense, signature, statute, term, trade, waiver, wording

Category 22

Animals, plants, and other life forms

Terms that refer to biological entities in technical and environmental contexts.

bacteria, bird, cassowary, cat, conifer, cow, dog, emu, fern, ferret, fungi, horse, insect, leopard, monkey, moss, mouse, pocket gopher, rose, termite, wombat