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Latency: <1ms Edge Availability: 99.99% Standard: ISO 6346 Clause 2.1 V8 Pure Compute

ISO 6346 Equipment Category Identifiers (U, J, Z)

Understand the 4th position equipment category identifier letters (U, J, Z) in container numbers.

Official Regulatory Standard & Verification Protocol Authority: Bureau International des Conteneurs (BIC) & ISO ↗

Quick Technical Summary: Understand the 4th position equipment category identifier letters (U, J, Z) in container numbers. Implementation conforms to ISO 6346 / BIC Container Prefix Coding.

Execution SLA
<1ms Edge (Cloudflare V8)
Governing Norm
ISO 6346 Clause 2.1
Throughput Limit
512 KB / Payload
Data Privacy
100% In-Memory (Zero Store)

Specification & Structural Breakdown

Position 4 in any valid 11-character ISO container number must be one of three accredited uppercase letters: U, J, or Z.

IdentifierEquipment TypeDescription
UFreight ContainerAll general cargo, reefer, tank, open-top, and flat-rack containers
JDetachable EquipmentClip-on generator sets (gensets), refrigeration units, detachable tanks
ZTrailers & ChassisIntermodal chassis, skeletal trailers, and bogies
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Test ISO 6346 Equipment Category Identifiers (U, J, Z) Live

Paste raw inputs up to 32KB and inspect deterministic parsed JSON in real-time across 330+ Cloudflare edge locations. Pure compute, zero cold-starts.

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Parsed JSON Response Model

The edge microservice transforms input payloads into strongly-typed hierarchical JSON with zero cold starts:

HTTP 200 JSON Payload
{
  "category": "U",
  "description": "Freight Container",
  "valid": true
}

Copy-Paste Integration Code

Integrate this validator directly into your application using your production API key:

cURL
curl --request POST \
  --url "https://iso-6346-container-chassis-check-digit-validator.stanzaapi.com/api/v1/container/validate" \
  --header "Content-Type: application/json" \
  --header "x-api-key: YOUR_API_KEY" \
  --data '{
  "containerNumber": "CSQU3054383",
  "sizeTypeCode": "45G1"
}'
Node.js (Fetch)
const response = await fetch("https://iso-6346-container-chassis-check-digit-validator.stanzaapi.com/api/v1/container/validate", {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
    "x-api-key": process.env.API_KEY || "YOUR_API_KEY"
  },
  body: JSON.stringify({
  "containerNumber": "CSQU3054383",
  "sizeTypeCode": "45G1"
})
});

const data = await response.json();
console.log(data);
Python (Requests)
import requests
import json

url = "https://iso-6346-container-chassis-check-digit-validator.stanzaapi.com/api/v1/container/validate"
headers = {
    "Content-Type": "application/json",
    "x-api-key": "YOUR_API_KEY"
}
payload = {
    "containerNumber": "CSQU3054383",
    "sizeTypeCode": "45G1"
}

response = requests.post(url, json=payload, headers=headers)
print(response.json())
Go
package main

import (
	"bytes"
	"fmt"
	"io"
	"net/http"
	"os"
)

func main() {
	url := "https://iso-6346-container-chassis-check-digit-validator.stanzaapi.com/api/v1/container/validate"
	payload := []byte(`{"containerNumber":"CSQU3054383","sizeTypeCode":"45G1"}`)

	req, _ := http.NewRequest("POST", url, bytes.NewBuffer(payload))
	req.Header.Add("Content-Type", "application/json")
	req.Header.Add("x-api-key", os.Getenv("API_KEY"))

	res, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)
	fmt.Println(string(body))
}

Frequently Asked Questions & Technical Notes

Are numbers with category identifiers other than U, J, or Z valid under ISO 6346?

No, any 4th character other than U, J, or Z is non-compliant with ISO 6346.

Related ISO 6346 Container & Chassis Check-Digit Validator API Formats

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