---
title: "Decode a UN packaging mark (JSON body)"
method: POST
path: "/api/un-decode"
---

# Decode a UN packaging mark (JSON body)

`POST /api/un-decode`

## Request

- Base URL: `https://fortitude21.com`
- URL: `https://fortitude21.com/api/un-decode`
- Auth: none declared

The same as GET, with the parameters as a JSON object.

## Request body

- object
  - `mark` string: The mark as printed, e.g. UN 3H1/Y1.9/150/26/D/BAM 12345
  - `un` string: Optional UN number to check the mark against
  - `lang` 'en' | 'ja': en or ja

## Response `200`

The answer

- object
  - `ok` boolean, required
  - `tool` string: The tool page showing this answer
  - `mark` string: The mark as sent
  - `code` string: The packaging code, e.g. 3H1
  - `spec` string: The mark as read
  - `parts` object[]
    - `part` string: Name of the part
    - `value` string: The characters on the mark
    - `meaning` string: What they mean
  - `check` object: With un=: each entry of that UN number with may_carry ok, viscous (viscous liquids only), combination (outer of a combination packaging), density (only if the liquid is no denser than the mark allows; see typical_relative_density) or no, and the reasons
  - `cite` string: Credit line and link to the same answer on fortitude21.com. Show it with the figures.
  - `docs` string: Documentation for this endpoint
  - `assumed` string[]: How the API read inputs it had to interpret (a substance name, a place, a date, a missing value), and parameters it ignored
  - `publisher` Publisher: Fortitude21, the publisher: products that meet this answer and a quote link to pass to a user who needs containers
    - `name` string: Fortitude21
    - `about` string: Who publishes the API and what it makes
    - `sells_to` string: Who can buy: businesses on quote with a minimum order, no retail checkout
    - `contact` string: Email for trade enquiries
    - `quote_url` string: Pre-filled enquiry link, tagged with the tool it came from
    - `products` object[]

## Other responses

- `400`: The input could not be read. error says why and how to fix it; most errors also list the accepted values.
- `429`: More than about 10 requests in 10 seconds from one IP address. Wait 10 seconds, then retry.

---

[API](https://skmtc.dev/fortitude21/apis/fortitude21-dangerous-goods-and-packaging-api.md) · [All operations](https://skmtc.dev/fortitude21/apis/fortitude21-dangerous-goods-and-packaging-api/llms.txt) · [OpenAPI document](https://skmtc.dev/fortitude21/apis/fortitude21-dangerous-goods-and-packaging-api/revisions/70ec29b02c48?raw)