# ISO 6346

ISO-code and dimension/load table at several newly washed containers

ISO 6346 is an international standard covering the coding, identification and marking of intermodal (shipping) containers used within containerized intermodal freight transport. The standard establishes a visual identification system for every container that includes a unique serial number (with check digit), the owner, a country code, a size, type and equipment category as well as any operational marks. The standard is managed by the International Container Bureau (BIC).

## Identification System

Example of an ISO 6346 conform container number:

### Owner Code

The owner code consists of three capital letters of the Latin alphabet to indicate the owner or principal operator of the container. Such code needs to be registered at the Bureau International des Conteneurs in Paris to ensure uniqueness worldwide.

### Equipment Category Identifier

The equipment category identifier consists of one of the following capital letters of the Latin alphabet:

• U for all freight containers
• J for detachable freight container-related equipment
• Z for trailers and chassis

Under the ISO code then only U J and Z are in use - the reefer container is identified by means of the size type code

### Serial Number

The serial number consists of 6 numberic digits, assigned by the owner or operator, uniquely identifying the container within that owner/operator's fleet.

### Check Digit

The check digit consists of one numeric digit providing a means of validating the recording and transmission accuracies of the owner code and serial number.

#### Calculation Step 1

An equivalent numerical value is assigned to each letter of the alphabet, beginning with 10 for the letter A (11 and multiples thereof are omitted):

 A B C D E F G H I J K L M 10 12 13 14 15 16 17 18 19 20 21 23 24
 N O P Q R S T U V W X Y Z 25 26 27 28 29 30 31 32 34 35 36 37 38

The individual digits of the serial number keep their numeric value.

#### Calculation Step 2

Each of the numbers calculated in step 1 is multiplied by 2position, where position is the exponent to base 2. Position starts at 0, from left to right.

The following table shows the multiplication factors:

 1. nbr 2. nbr 3. nbr 4. nbr 5. nbr 6. nbr 7. nbr 8. nbr 9. nbr 10. nbr 20 21 22 23 24 25 26 27 28 29 1 2 4 8 16 32 64 128 256 512

#### Calculation Step 3

a) Sum up all results of step 2
b) Divide them by 11
c) Round the result down to zero i.e. make the result a whole number (integer)
d) Multiply the integer value by 11
e) Subtract result of d) from result of a): This is the check digit!

If the final difference is 10, then the check digit becomes 0. To ensure that this does not happen, the standard recommends that serial numbers should not be used which produce a final difference of 10, however there are containers in the market which do not follow this recommendation, so handling this case has to be included if a check digit calculator is programmed.

Notice that step b) to e) is a calculation of the remainder found after division of a) by 11. Most programming languages have a modulo operator for this. Attention should be paid on how it is working in the language chosen; i. e. if it is giving back the decimal rest or the integer rest in order to get proper results. 11 is used as divisor because a container number has 11 letters and digits in total. In step 1 the numbers 11, 22 and 33 are left out as they are multiples of the divisor.

#### Example

 C S Q U 3 0 5 4 3 8 Calc. 13 30 28 32 3 0 5 4 3 8 x x x x x x x x x x 1 2 4 8 16 32 64 128 256 512 = = = = = = = = = = 13 60 112 256 48 0 320 512 768 4096 6185 [a)] b) Division by 11: 562.272... c) Erase decimal digits: 562 d) Multiply by 11: 6182 a) minus d) = Check Digit: 3

#### Code Sample 1

Below is a code Snippet implementing the above algorithm in MATLAB validating string "cid":

%% Step 1
char2num = [10 12 13 14 15 16 17 18 19 20 21 23 24 25 26 27 28 29 30 31 32 34 35 36 37 38];
msk = logical([1 1 1 1 0 0 0 0 0 0 0]);  % mask separating digits from numbers
cid( msk) = char2num(cid( msk)-'A'+1);   % letters to numbers conversion
cid(~msk) =          cid(~msk)-'1'+1;    % digit characters to numbers conversion
vec = double(cid);
%% Step 2
num  = sum(vec(1:10).* 2.^(0:9));
%% Step 3
check_digit = mod(mod(num,11),10);
valid = (check_digit==vec(11));

#### Code Sample 2

Below is the Visual Basic (VBA) code to create a custom "ISO6346Check" function in Microsoft Excel (Alt + F11) that returns the correct check digit:

Function ISO6346Check(k As String) ' Calculates the ISO Shipping Container Check Digit
Dim i%, s&
Application.Volatile
For i = 1 To 10
s = s + IIf(i < 5, Fix(11 * (Asc(Mid(k, i)) - 56) / 10) + 1, Asc(Mid(k, i)) - 48) * 2 ^ (i - 1)
Next i
ISO6346Check = (s - Fix(s / 11) * 11) Mod 10
End Function

#### Code Sample 3

Below is Python (2.7) code to validate the string "cid":

cid = 'CSQU3054383'
first10 = cid[0:10]
check = cid[10:11]
char2num = {'0':0,'1':1,'2':2,'3':3,'4':4,'5':5,'6':6,'7':7,'8':8,'9':9,
'A':10,'B':12,'C':13,'D':14,'E':15,'F':16,'G':17,'H':18,'I':19,'J':20,'K':21,'L':23,'M':24,
'N':25,'O':26,'P':27,'Q':28,'R':29,'S':30,'T':31,'U':32,'V':34,'W':35,'X':36,'Y':37,'Z':38,}
x = 0
sum = 0
for c in first10:
sum += (char2num[c] * 2**x)
x += 1
print (sum-int(sum/11.0)*11)%10 == char2num[check]

#### Code Sample 4

Below is the Javascript code to create a custom "ISO6346Check":

function ISO6346Check(cntrNum) {
var num = 0;
var charCode = "0123456789A?BCDEFGHIJK?LMNOPQRSTU?VWXYZ";
if (!cntrNum || cntrNum.length != 11) {
return false;
}
cntrNum = cntrNum.toUpperCase();
for (var i = 0; i < 10; i++) {
var chr = cntrNum.substring(i, i + 1);
var idx = chr == '?' ? -1 : charCode.indexOf(chr);
if (idx < 0) {
return false;
}
idx = idx * Math.pow(2, i);
num += idx;
}
num = (num % 11) % 10;
return parseInt(cntrNum.substring(10, 11)) == num;
}

#### Code Sample 5

Below is the Excel Formula to validate container number in Cell A1[citation needed]

=IF((MID(A1,11,1)*1)=(1*SUBSTITUTE((IF(MID(A1,1,1)="A",10,IF(MID(A1,1,1)="B",12,IF(MID(A1,1,1)="C",13,IF(MID(A1,1,1)="D",14,
IF(MID(A1,1,1)="E",15,IF(MID(A1,1,1)="F",16,IF(MID(A1,1,1)="G",17,IF(MID(A1,1,1)="H",18,IF(MID(A1,1,1)="I",19,
IF(MID(A1,1,1)="J",20,IF(MID(A1,1,1)="K",21,IF(MID(A1,1,1)="L",23,IF(MID(A1,1,1)="M",24,IF(MID(A1,1,1)="N",25,
IF(MID(A1,1,1)="O",26,IF(MID(A1,1,1)="P",27,IF(MID(A1,1,1)="Q",28,IF(MID(A1,1,1)="R",29,IF(MID(A1,1,1)="S",30,
IF(MID(A1,1,1)="T",31,IF(MID(A1,1,1)="U",32,IF(MID(A1,1,1)="V",34,IF(MID(A1,1,1)="W",35,IF(MID(A1,1,1)="X",36,
IF(MID(A1,1,1)="Y",37,IF(MID(A1,1,1)="Z",38,FALSE)))))))))))))))))))))))))))+
(IF(MID(A1,2,1)="A",10,IF(MID(A1,2,1)="B",12,IF(MID(A1,2,1)="C",13,IF(MID(A1,2,1)="D",14,IF(MID(A1,2,1)="E",15,
IF(MID(A1,2,1)="F",16,IF(MID(A1,2,1)="G",17,IF(MID(A1,2,1)="H",18,IF(MID(A1,2,1)="I",19,IF(MID(A1,2,1)="J",20,
IF(MID(A1,2,1)="K",21,IF(MID(A1,2,1)="L",23,IF(MID(A1,2,1)="M",24,IF(MID(A1,2,1)="N",25,IF(MID(A1,2,1)="O",26,
IF(MID(A1,2,1)="P",27,IF(MID(A1,2,1)="Q",28,IF(MID(A1,2,1)="R",29,IF(MID(A1,2,1)="S",30,IF(MID(A1,2,1)="T",31,
IF(MID(A1,2,1)="U",32,IF(MID(A1,2,1)="V",34,IF(MID(A1,2,1)="W",35,IF(MID(A1,2,1)="X",36,IF(MID(A1,2,1)="Y",37,
IF(MID(A1,2,1)="Z",38,FALSE))))))))))))))))))))))))))*2)+(IF(MID(A1,3,1)="A",10,IF(MID(A1,3,1)="B",12,IF(MID(A1,3,1)="C",13,IF(MID(A1,3,1)="D",14,IF(MID(A1,3,1)="E",15,
IF(MID(A1,3,1)="F",16,IF(MID(A1,3,1)="G",17,IF(MID(A1,3,1)="H",18,IF(MID(A1,3,1)="I",19,IF(MID(A1,3,1)="J",20,
IF(MID(A1,3,1)="K",21,IF(MID(A1,3,1)="L",23,IF(MID(A1,3,1)="M",24,IF(MID(A1,3,1)="N",25,IF(MID(A1,3,1)="O",26,
IF(MID(A1,3,1)="P",27,IF(MID(A1,3,1)="Q",28,IF(MID(A1,3,1)="R",29,IF(MID(A1,3,1)="S",30,IF(MID(A1,3,1)="T",31,
IF(MID(A1,3,1)="U",32,IF(MID(A1,3,1)="V",34,IF(MID(A1,3,1)="W",35,IF(MID(A1,3,1)="X",36,IF(MID(A1,3,1)="Y",37,
IF(MID(A1,3,1)="Z",38,FALSE))))))))))))))))))))))))))*4)+(IF(MID(A1,4,1)="A",10,IF(MID(A1,4,1)="B",12,IF(MID(A1,4,1)="C",13,IF(MID(A1,4,1)="D",14,IF(MID(A1,4,1)="E",15,
IF(MID(A1,4,1)="F",16,IF(MID(A1,4,1)="G",17,IF(MID(A1,4,1)="H",18,IF(MID(A1,4,1)="I",19,IF(MID(A1,4,1)="J",20,
IF(MID(A1,4,1)="K",21,IF(MID(A1,4,1)="L",23,IF(MID(A1,4,1)="M",24,IF(MID(A1,4,1)="N",25,IF(MID(A1,4,1)="O",26,
IF(MID(A1,4,1)="P",27,IF(MID(A1,4,1)="Q",28,IF(MID(A1,4,1)="R",29,IF(MID(A1,4,1)="S",30,IF(MID(A1,4,1)="T",31,
IF(MID(A1,4,1)="U",32,IF(MID(A1,4,1)="V",34,IF(MID(A1,4,1)="W",35,IF(MID(A1,4,1)="X",36,IF(MID(A1,4,1)="Y",37,
IF(MID(A1,4,1)="Z",38,FALSE))))))))))))))))))))))))))*8)+(MID(A1,5,1)*16)+(MID(A1,6,1)*32)+(MID(A1,7,1)*64)+(MID(A1,8,1)*128)+(MID(A1,9,1)*256)+(MID(A1,10,1)*512)-11*ROUNDDOWN((((IF(MID(A1,1,1)="A",10,IF(MID(A1,1,1)="B",12,IF(MID(A1,1,1)="C",13,
IF(MID(A1,1,1)="D",14,IF(MID(A1,1,1)="E",15,IF(MID(A1,1,1)="F",16,IF(MID(A1,1,1)="G",17,IF(MID(A1,1,1)="H",18,
IF(MID(A1,1,1)="I",19,IF(MID(A1,1,1)="J",20,IF(MID(A1,1,1)="K",21,IF(MID(A1,1,1)="L",23,IF(MID(A1,1,1)="M",24,
IF(MID(A1,1,1)="N",25,IF(MID(A1,1,1)="O",26,IF(MID(A1,1,1)="P",27,IF(MID(A1,1,1)="Q",28,IF(MID(A1,1,1)="R",29,
IF(MID(A1,1,1)="S",30,IF(MID(A1,1,1)="T",31,IF(MID(A1,1,1)="U",32,IF(MID(A1,1,1)="V",34,IF(MID(A1,1,1)="W",35,
IF(MID(A1,1,1)="X",36,IF(MID(A1,1,1)="Y",37,IF(MID(A1,1,1)="Z",38,FALSE)))))))))))))))))))))))))))+(IF(MID(A1,2,1)="A",10,IF(MID(A1,2,1)="B",12,IF(MID(A1,2,1)="C",13,IF(MID(A1,2,1)="D",14,IF(MID(A1,2,1)="E",15,
IF(MID(A1,2,1)="F",16,IF(MID(A1,2,1)="G",17,IF(MID(A1,2,1)="H",18,IF(MID(A1,2,1)="I",19,IF(MID(A1,2,1)="J",20,
IF(MID(A1,2,1)="K",21,IF(MID(A1,2,1)="L",23,IF(MID(A1,2,1)="M",24,IF(MID(A1,2,1)="N",25,IF(MID(A1,2,1)="O",26,
IF(MID(A1,2,1)="P",27,IF(MID(A1,2,1)="Q",28,IF(MID(A1,2,1)="R",29,IF(MID(A1,2,1)="S",30,IF(MID(A1,2,1)="T",31,
IF(MID(A1,2,1)="U",32,IF(MID(A1,2,1)="V",34,IF(MID(A1,2,1)="W",35,IF(MID(A1,2,1)="X",36,IF(MID(A1,2,1)="Y",37,
IF(MID(A1,2,1)="Z",38,FALSE))))))))))))))))))))))))))*2)+(IF(MID(A1,3,1)="A",10,IF(MID(A1,3,1)="B",12,IF(MID(A1,3,1)="C",13,IF(MID(A1,3,1)="D",14,IF(MID(A1,3,1)="E",15,
IF(MID(A1,3,1)="F",16,IF(MID(A1,3,1)="G",17,IF(MID(A1,3,1)="H",18,IF(MID(A1,3,1)="I",19,IF(MID(A1,3,1)="J",20,
IF(MID(A1,3,1)="K",21,IF(MID(A1,3,1)="L",23,IF(MID(A1,3,1)="M",24,IF(MID(A1,3,1)="N",25,IF(MID(A1,3,1)="O",26,
IF(MID(A1,3,1)="P",27,IF(MID(A1,3,1)="Q",28,IF(MID(A1,3,1)="R",29,IF(MID(A1,3,1)="S",30,IF(MID(A1,3,1)="T",31,
IF(MID(A1,3,1)="U",32,IF(MID(A1,3,1)="V",34,IF(MID(A1,3,1)="W",35,IF(MID(A1,3,1)="X",36,IF(MID(A1,3,1)="Y",37,
IF(MID(A1,3,1)="Z",38,FALSE))))))))))))))))))))))))))*4)+(IF(MID(A1,4,1)="A",10,IF(MID(A1,4,1)="B",12,IF(MID(A1,4,1)="C",13,IF(MID(A1,4,1)="D",14,IF(MID(A1,4,1)="E",15,
IF(MID(A1,4,1)="F",16,IF(MID(A1,4,1)="G",17,IF(MID(A1,4,1)="H",18,IF(MID(A1,4,1)="I",19,IF(MID(A1,4,1)="J",20,
IF(MID(A1,4,1)="K",21,IF(MID(A1,4,1)="L",23,IF(MID(A1,4,1)="M",24,IF(MID(A1,4,1)="N",25,IF(MID(A1,4,1)="O",26,
IF(MID(A1,4,1)="P",27,IF(MID(A1,4,1)="Q",28,IF(MID(A1,4,1)="R",29,IF(MID(A1,4,1)="S",30,IF(MID(A1,4,1)="T",31,
IF(MID(A1,4,1)="U",32,IF(MID(A1,4,1)="V",34,IF(MID(A1,4,1)="W",35,IF(MID(A1,4,1)="X",36,IF(MID(A1,4,1)="Y",37,
IF(MID(A1,4,1)="Z",38,FALSE))))))))))))))))))))))))))*8)+(MID(A1,5,1)*16)+(MID(A1,6,1)*32)+(MID(A1,7,1)*64)+(MID(A1,8,1)*128)+(MID(A1,9,1)*256)+(MID(A1,10,1)*512))/11),0),10,0)),"VALID","INVALID")

### Practical Problems

In day-to-day business it happens that containers do appear which do not follow the ISO 6346 identification at all, however they are fully CSC safety approved containers. Usually these are "shippers owned" containers, which means that they are not owned by the carrier but supplied by the cargo owners (shippers). They may have no registered owner code and no category identifier and have no check digit. It is advisable to follow ISO 6346 as the absence of a compliant identification code causes problems for both carriers and container terminals to correctly identify the equipment and properly deliver the cargo, because computer systems require ISO 6346 conformant naming and as such missing prefixes are invented. For example YYYY at the carrier and XXXX at the terminal causes the equipment to mismatch. Moreover, since ISO 6346 identification has become a requirement in international Customs conventions (Customs Conventions on Containers and Istanbul Convention), many Customs Administrations have begun validating that containers are marked as per the standard.

## Size and Type Codes

The codes are compiled of the following elements:

• First character, representing the length (coded)
• Second character, representing the width and height (coded)
• Third and fourth character indicating the type of the container

The following is an overview of the most common codes:

 ISO Type Group ISO Size Type Code Description Code Description 20GP GENERAL PURPOSE CONT. 20G0 GENERAL PURPOSE CONT. 20G1 GENERAL PURPOSE CONT. 20HR ISOLADO CONTAINE REEFER 20H0 INSULATED CONTAINER 20PF FLAT (FIXED ENDS) 20P1 FLAT (FIXED ENDS) 20TD TANK CONTAINER 20T3 TANK CONTAINER 20T4 TANK CONTAINER 20T5 TANK CONTAINER 20T6 TANK CONTAINER 20TG TANK CONTAINER 20T7 TANK CONTAINER 20T8 TANK CONTAINER 20TN TANK CONTAINER 20T0 TANK CONTAINER 20T1 TANK CONTAINER 20T2 TANK CONTAINER 22BU BULK CONTAINER 22B0 BULK CONTAINER 22GP GENERAL PURPOSE CONT. 22G0 GENERAL PURPOSE CONT. 22G1 GENERAL PURPOSE CONT. 22HR INSULATED CONTAINER 22H0 INSULATED CONTAINER 22PC FLAT (COLLAPSIBLE) 22P3 FLAT (COLLAPSIBLE) 22P8 FLAT (COLL.FLUSH FOLDING) 22P9 FLAT (COLLAPSIBLE) 22PF FLAT (FIXED ENDS) 22P1 FLAT (FIXED ENDS) 22P7 FLAT (GENSET CARRIER) 22RC REEFER CONT.(NO FOOD) 22R9 REEFER CONT.(NO FOOD) 22RS BUILT-IN GEN. F. POWER SPLY OF REEF 22R7 BUILT-IN GEN. F. POWER SPLY OF REEF 22RT REEFER CONTAINER 22R1 REEFER CONTAINER 22SN NAMED CARGO CONTAINER 22S1 NAMED CARGO CONTAINER 22TD TANK CONTAINER 22T3 TANK CONTAINER 22T4 TANK CONTAINER 22T5 TANK CONTAINER 22T6 TANK CONTAINER 22TG TANK CONTAINER 22T7 TANK CONTAINER 22T8 TANK CONTAINER 22TN TANK CONTAINER 22T0 TANK CONTAINER 22T1 TANK CONTAINER 22T2 TANK CONTAINER 22UP HARDTOP CONTAINER 22U6 HARDTOP CONTAINER 22UT OPEN TOP CONTAINER 22U1 OPEN TOP CONTAINER 22VH VENTILATED CONTAINER 22V0 VENTILATED CONTAINER 22V2 VENTILATED CONTAINER 22V3 VENTILATED CONTAINER 25GP GP-CONTAINER OVER-HEIGHT 25G0 GP-CONTAINER OVER-HEIGHT 26GP GP-CONTAINER OVER-HEIGHT 26G0 GP-CONTAINER OVER-HEIGHT 26HR INSULATED CONTAINER 26H0 INSULATED CONTAINER 28TG TANK FOR GAS 28T8 TANK FOR GAS 28UT OPEN TOP (HALF HEIGHT) 28U1 OPEN TOP (HALF HEIGHT) 28VH VE-HALF-HEIGHT =1448 MM HEIGHT 28V0 VE-HALF-HEIGHT =1448 MM HEIGHT 29PL PLATFORM 29P0 PLATFORM 2EGP GEN. PURP. WITHOUT VENT WIDTH 2.5M 2EG0 HIGH CUBE CONT. (WIDTH 2.5M) 42GP GENERAL PURPOSE CONT. 42G0 GENERAL PURPOSE CONT. 42G1 GENERAL PURPOSE CONT. 42HR INSULATED CONTAINER 42H0 INSULATED CONTAINER 42PC FLAT (COLLAPSIBLE) 42P3 FLAT (COLLAPSIBLE) 42P8 FLAT (COLL.FLUSH FOLDING) 42P9 FLAT (COLLAPSIBLE) 42PF FLAT (FIXED ENDS) 42P1 FLAT (FIXED ENDS) 42PS FLAT (SPACE SAVER) 42P6 FLAT SPACE SAVER 42RC REEFER CONT.(NO FOOD) 42R9 REEFER CONT.(NO FOOD) 42RS REEFER CONT.(DIESEL GEN.) 42R3 REEFER CONT.(DIESEL GEN.) 42RT REEFER CONTAINER 42R1 REEFER CONTAINER 42SN NAMED CARGO CONTAINER 42S1 NAMED CARGO CONTAINER 42TD TANK CONTAINER 42T5 TANK CONTAINER 42T6 TANK CONTAINER 42TG TANK CONTAINER 42T8 TANK CONTAINER 42TN TANK CONTAINER 42T2 TANK CONTAINER 42UP HARDTOP CONTAINER 42U6 HARDTOP CONTAINER 42UT OPEN TOP CONTAINER 42U1 OPEN TOP CONTAINER 45BK BULK CONTAINER 45B3 BULK CONTAINER 45GP HIGH CUBE CONT. 45G0 HIGH CUBE CONT. 45G1 HIGH CUBE CONT. 45PC FLAT (COLLAPSIBLE) 45P3 FLAT (COLLAPSIBLE) 45P8 FLAT (COLL.FLUSH FOLDING) 45RC REEFER CONT.(NO FOOD) 45R9 REEFER CONT.(NO FOOD) 45RT REEFER HIGHCUBE CONTAINER 45R1 REEFER HIGHCUBE CONTAINER 45UT OPEN TOP CONTAINER 45U1 OPEN TOP CONTAINER 45UP HIGH CUBE HARDTOP CONT. 45U6 HIGH CUBE HARDTOP CONT. 46HR INSULATED CONTAINER 46H0 INSULATED CONTAINER 48TG TANK FOR GAS 48T8 TANK FOR GAS 49PL PLATFORM 49P0 PLATFORM 4CGP GP CONTAINER 4CG0 GP CONTAINER (WIDTH 2.5 M) L0GP HIGH CUBE CONT. L0G1 HIGH CUBE CONT. L2GP HIGH CUBE CONT. L2G1 HIGH CUBE CONT. L5GP HIGH CUBE CONT. L5G1 HIGH CUBE CONT.

Use the below to calculate Size/Type of a less commonly used ISO 6346 containers:

 ISO Length Codes Second size code character Code Container length Code Container height Width 1 10′ 0 8′ 8′ 2 20′ 2 8′6″ 3 30′ 4 9′ 4 40′ 5 9′6″ B 24′ 6 > 9′6″ C 24′6″ 8 4′3″ G 41′ 9 <= 4′ H 43′ C 8′6″ 2348mm < x <= 2500mm L 45′ D 9′ M 48′ E 9′6″ N 49′ F > 9′6″
 ISO Type Codes Code Description G0 General - Openings at one or both ends G1 General - Passive vents at upper part of cargo space G2 General - Openings at one or both ends + full openings on one or both sides G3 General - Openings at one or both ends + partial openings on one or both sides V0 Fantainer - Non-mechanical, vents at lower and upper parts of cargo space V2 Fantainer - Mechanical ventilation system located internally V4 Fantainer - Mechanical ventilation system located externally R0 Integral Reefer - Mechanically refrigerated R1 Integral Reefer - Mechanically refrigerated and heated R2 Integral Reefer - Self-powered mechanically refrigerated R3 Integral Reefer - Self-powered mechanically refrigerated and heated H0 Refrigerated or heated with removable equipment located externally; heat transfer coefficient K=0.4W/M2.K H1 Refrigerated or heated with removable equipment located internally H2 Refrigerated or heated with removable equipment located externally; heat transfer coefficient K=0.7W/M2.K H5 Insulated - Heat transfer coefficient K=0.4W/M2.K H6 Insulated - Heat transfer coefficient K=0.7W/M2.K U0 Open Top - Openings at one or both ends U1 Open Top - Idem + removable top members in end frames U2 Open Top - Openings at one or both ends + openings at one or both sides U3 Open Top - Idem + removable top members in end frames U4 Open Top - Openings at one or both ends + partial on one and full at other side U5 Open Top - Complete, fixed side and end walls ( no doors ) T0 Tank - Non dangerous liquids, minimum pressure 0.45 bar T1 Tank - Non dangerous liquids, minimum pressure 1.50 bar T2 Tank - Non dangerous liquids, minimum pressure 2.65 bar T3 Tank - Dangerous liquids, minimum pressure 1.50 bar T4 Tank - Dangerous liquids, minimum pressure 2.65 bar T5 Tank - Dangerous liquids, minimum pressure 4.00 bar T6 Tank - Dangerous liquids, minimum pressure 6.00 bar T7 Tank - Gases, minimum pressure 9.10 bar T8 Tank - Gases, minimum pressure 22.00 bar T9 Tank - Gases, minimum pressure to be decided B0 Bulk - Closed B1 Bulk - Airtight B3 Bulk - Horizontal discharge, test pressure 1.50 bar B4 Bulk - Horizontal discharge, test pressure 2.65 bar B5 Bulk - Tipping discharge, test pressure 1.50 bar B6 Bulk - Tipping discharge, test pressure 2.65 bar P0 Flat or Bolster - Plain platform P1 Flat or Bolster - Two complete and fixed ends P2 Flat or Bolster - Fixed posts, either free-standing or with removable top member P3 Flat or Bolster - Folding complete end structure P4 Flat or Bolster - Folding posts, either free-standing or with removable top member P5 Flat or Bolster - Open top, open ends (skeletal) S0 Livestock carrier S1 Automobile carrier S2 Live fish carrier

## Country Code (Optional)

The country code consists of two capital letters of the Latin alphabet as described in ISO 3166. It indicates the country where the code is registered not the nationality of the owner or operator of the container. The letters of the code shall not be less than 100 mm high.

## Mandatory Operational Marks

Operational marks are intended solely to convey information requested for the movement of containers or give visual warnings. They relate to

• the weight of containers
• a symbol to denote air-surface container
• a sign warning of overhead electrical danger
• height marks for containers higher than 2.6 m (8 ft 6 in)

## References

The following is a list of further freight container related ISO specifications, where not all have an article assigned yet (you can help improve Wikipedia and start one):

• ISO 668 - Freight containers - Classification, dimensions and ratings
• ISO 830 - Freight containers - Terminology
• ISO 1161 - Freight containers - Corner fittings - Specification
• ISO 1496 - Freight containers - Specification and testing
• ISO 2308 - Hooks for lifting freight containers of up to 30 tons capacity - Basic requirements
• ISO 3874 - Freight containers - Handling and securing
• ISO 8323 - Freight containers - Air/surface (intermodal) general purpose containers - Specification and tests
• ISO 9669 - Freight containers - Interface connections for tank containers
• ISO 9711 - Freight containers - Information related to containers on board vessels
• ISO 9897 - Container equipment data exchange (CEDEX)
• ISO 10368 - Freight thermal containers - Remote condition monitoring
• ISO 10374 - Freight containers - Automatic identification