ECE R7, R6 and R91 Explained: Signal Lamp Categories and Approval Marks
ECE R7 sets the approval requirements for front and rear position lamps, stop lamps and end-outline marker lamps. With ECE R6 for direction indicators and ECE R91 for side-marker lamps, it covers the signal lamps on almost every road vehicle registered in a country that applies the UN 1958 Agreement. Each regulation defines lamp categories, colours, intensity limits and the approval mark on the lens.
All three were frozen by the 2019 simplification of the UN lighting regulations, yet their marks are on most lamps in service and in many spares lists. This guide explains what each regulation requires, how to read the mark, where the regulations stand in 2026 and what that means for military and specialist vehicles.
ECE R6: Direction Indicator Categories
UN Regulation No. 6 covers direction indicators for power-driven vehicles and their trailers in categories L, M, N, O and T. The light must be amber. Its 01 series of amendments entered into force in 1987 and governed approvals for more than three decades; the 02 series of 2019 only added the provisions that phase the regulation out.
R6 does not approve a generic indicator. It approves a category, and the category fixes where on the vehicle the lamp may be used:
- Category 1, 1a and 1b (front): chosen by distance from the dipped-beam headlamp or front fog lamp: 40 mm or more for category 1, more than 20 mm but less than 40 mm for 1a, and 20 mm or less for 1b. The closer the indicator sits to a bright headlamp, the higher its minimum intensity, so that the flash is not lost in the glare.
- Category 2a and 2b (rear): 2a has a steady luminous intensity, 2b a variable one.
- Category 5 and 6 (side): supplementary side indicators, used together with front and rear indicators. Category 5 is for M1 vehicles and for N1, M2 and M3 vehicles up to 6 m long; category 6 is for N2 and N3 vehicles and longer M2 and M3 vehicles. An N3 military logistics truck therefore needs category 6 side indicators, not the small category 5 repeaters used on cars.
The flash rate is not an R6 requirement. R6 only uses a switching frequency of 1.5 ± 0.5 Hz as a test condition; the rate on the vehicle, 90 ± 30 flashes per minute, is set by UN Regulation No. 48, the installation regulation. An indicator may share a housing with other functions, for example in a combined rear lamp, but the indicator function must meet the R6 photometry on its own.
ECE R7: Position, Stop and End-Outline Lamps
UN Regulation No. 7 covers front and rear position lamps and stop lamps for vehicles of categories L, M, N, O and T, and end-outline marker lamps for categories M, N, O and T. The 02 series of amendments, in force since 1991, carried the technical requirements until the freeze; the 03 series of 2019 added the phase-out provisions. Front lamps emit white light and rear lamps red.
Each function has its own symbol on the approval mark:
- A: front position lamp. AM: front end-outline marker lamp.
- R, R1 and R2: rear position lamp, with steady (R, R1) or variable (R2) intensity. RM1 and RM2: rear end-outline marker lamp, steady or variable.
- S1 and S2: stop lamp, steady or variable intensity. S3 and S4: the stop lamp categories used as the centre high-mounted stop lamp, steady or variable.
End-outline marker lamps sit near the extreme outer edges and top of the vehicle to show its overall width. On a wide military truck, a shelter body or a bridging vehicle, they are what tells other drivers at night how much road the vehicle takes up.
Where a rear position lamp is reciprocally incorporated with a stop lamp, R7 requires the ratio of their intensities to be at least 5:1 in the central field (±5° V, ±10° H). The reason is practical: if the two functions are too close in brightness, a following driver cannot tell braking from steady running. When comparing multi-function units such as those in our LED rear lights range, check the symbol of each function rather than a single standards line.
ECE R91: Side Markers SM1 and SM2
UN Regulation No. 91 covers side-marker lamps for vehicles of categories M, N, O and T: lamps that make the vehicle recognisable from the side. It entered into force in 1993; its original series held the technical requirements, and the 01 series of 2019 added the phase-out provisions. There are two categories:
- SM1: for all vehicle categories. At least 4 cd on the reference axis and a horizontal field of ±45°.
- SM2: for M1 vehicles (passenger cars) only. At least 0.6 cd and a field of ±30°.
For trucks, trailers and armoured transports this means SM1 in every case, whatever the vehicle length. Side-marker light is amber; the rearmost side-marker lamp may be red when it is grouped, combined or reciprocally incorporated with the rear position lamp or certain other rear lamps.
How many side markers a vehicle needs and how far apart they sit is not an R91 matter. Presence, number and spacing are installation requirements in UN Regulation No. 48, so an approved lamp can still be fitted non-compliantly, which happens most often on long trailers and special bodies. Our LED side marker lights (Model 420022) are listed to ECE Reg 6, 7 and 91.
Intensity Limits by Lamp Category
Every category has a minimum and a maximum luminous intensity in the reference axis. The minimum makes the signal visible; the maximum prevents glare and keeps one function from drowning out another. A brighter lamp is therefore not automatically a better one: above the maximum it falls outside its category. Values below are for a single lamp; a lamp marked D for use in an assembly of two has half the maximum.
| Function and symbol | Minimum (cd) | Maximum (cd) |
|---|---|---|
| Front direction indicator, 1 / 1a / 1b (R6) | 175 / 250 / 400 | 1,000 / 1,200 / 1,200 |
| Rear direction indicator, 2a / 2b (R6) | 50 / 50 | 500 / 1,000 |
| Side direction indicator, 5 / 6 (R6) | 0.6 / 50 | 280 / 280 |
| Front position lamp, A (R7) | 4 | 140 |
| Rear position lamp, R or R1 / R2 (R7) | 4 / 4 | 17 / 42 |
| Stop lamp, S1 / S2 (R7) | 60 / 60 | 260 / 730 |
| Centre high-mounted stop lamp, S3 / S4 (R7) | 25 / 25 | 110 / 160 |
| Side-marker lamp, SM1 / SM2 (R91) | 4 / 0.6 | 25 / 25 |
Sources: UN R6 (01 series, Supplement 25) and UN R7 (02 series, Supplement 23) as published in the Official Journal in 2014; SM1 and SM2 values from UN R148 (OJ L 347, 2021), which carried the R91 requirements over unchanged.
How to Read an ECE Approval Mark
The approval mark is the only proof on the lamp itself that a type approval exists. A datasheet that says “conforms to ECE R7” is a claim; a mark is the result of tests by a technical service and an approval granted by a national authority. A lamp without the mark has no ECE approval, whatever the supplier states.
Status in 2026: Frozen Since the 2019 Simplification
On 15 November 2019, UN Regulation No. 148 on light-signalling devices entered into force. It combines the provisions of nine device regulations, Nos. 4, 6, 7, 23, 38, 50, 77, 87 and 91, into one text. The consolidation was editorial: the technical requirements of R6, R7 and R91 moved across unchanged. New lamps approved to it carry 148R and the series in the mark instead of a bare approval number, as explained in our article on ECE R148.
The old regulations were not withdrawn but frozen. On 15 October 2019 each received a final series of amendments whose only purpose was the phase-out: the 02 series of R6, the 03 series of R7 and the 01 series of R91. According to the Netherlands approval authority RDW, no new approvals are granted to R6 or R7 from 15 October 2021, while extensions of existing approvals remain possible.
For buyers this has three consequences. A lamp marked under R6, R7 or R91 keeps its approval and is still a valid part. A newly approved lamp type carries an R148 approval instead, with the same categories and symbols. And a specification that demands “ECE R7” alone may exclude the newest designs, so it is better to name the function and category and accept an approval under either regulation. How these device approvals fit into vehicle approval in Europe is covered in our guide to EU vehicle lighting regulations.
Why This Matters for Tactical Vehicles
Military procurement tends to concentrate on MIL-STD and NATO requirements, and ECE approval is often an afterthought. In the EU, the framework regulation for motor vehicle approval does not apply to vehicles designed and constructed or adapted for use by the armed services only (Regulation (EU) 2018/858, Article 2(2)(d)). A purpose-built military platform can therefore sit outside the type-approval system, and its lighting is then whatever the contract and national military rules specify.
The exclusion is narrower than it looks. Commercially derived trucks, trailers bought off the shelf and vehicles registered for civil use fall back under the normal rules, and many fleets specify road-legal signal lamps anyway so that vehicles can move on public roads between bases, ranges and exercise areas without special arrangements. MIL-STD or NATO compliance does not replace an ECE approval, and an ECE approval says nothing about environmental or electromagnetic performance.
Many tactical rear and front lamps are therefore dual-function. The road functions carry R6, R7 or R148 approvals; the blackout functions fall outside the UN system and follow STANAG 4381. Both share one housing, so ask for the approval mark of every road function and the military specification of every blackout function before acceptance. For a lamp schedule that has to satisfy both, send us the vehicle category, the countries of registration and the functions required at info@betalight-tactical.com.
Frequently Asked Questions
Yes, between Contracting Parties that apply the same regulation. The 1958 Agreement has 62 Contracting Parties, including the European Union, the United Kingdom and Japan, and each party that applies R6, R7 or R91 accepts lamps approved to it by the others. A lamp marked E1 by the German authority is therefore accepted in the Netherlands or France. The United States and Canada are not parties, so an ECE mark alone does not make a lamp legal there.
Yes, and multi-function lamps usually do. A rear lamp cluster may carry R7 symbols for its position and stop functions (for example R1-S1) and an R6 category for its indicator, and a side lamp may combine a category 5 or 6 indicator with an SM1 side marker. Each function is tested and marked separately, so check that every function you intend to use appears in the mark.
UN Regulation No. 48 requires indicators to flash 90 ± 30 times per minute and the driver’s tell-tale to show a lamp failure, for example by a marked change of frequency. Many vehicle circuits detect failure from the current drawn. An LED indicator draws far less current than a filament bulb, so the circuit can read it as a failed lamp and flash fast. The lamp’s R6 approval is not the problem: the flasher or load must be matched to the LED lamp.