What do the markings on a pallet mean?

A wheat symbol, two letters, a number, and two more letters. That last pair is the one people are looking for: it says which treatment the wood was given before it was allowed to cross a border.

This reads the stamp against 7 CFR 319.40-3, which describes the mark in its own words and carries no copyright.

What the mark must contain

“The mark must be approved by the International Plant Protection Convention in its International Standards for Phytosanitary Measures to certify that wood packaging material has been subjected to an approved measure, and must include a unique graphic symbol, the ISO two-letter country code for the country that produced the wood packaging material, a unique number assigned by the national plant protection agency of that country to the producer of the wood packaging material, and an abbreviation disclosing the type of treatment (e.g., HT for heat treatment or MB for methyl bromide fumigation).”

The layout is a picture with nothing written on it

Having described the contents, the regulation says:

“The currently approved format for the mark is as follows, where XX would be replaced by the country code, 000 by the producer number, and YY by the treatment type (HT or MB):”

— and then embeds a figure. In the published XML that figure is <GPH><GID>ER16SE04.000</GID></GPH>: a file identifier, and no caption, no alt text and no description of any kind. So XX, 000 and YY are the whole of what the regulation says in words about where things sit, and they are all this page uses.

That is the exact mirror of the EPA engine family page, where the structure was stated in a diagram’s alt text and nowhere else. Here there is not even that. Both pages say which thread they are hanging from.

HT, MB, and the two most important letters in the sentence

Those two are introduced by “e.g.”. The regulation is not giving a list; it is giving examples, and saying so. ISPM 15 — the international standard the CFR points at — defines others.

So a treatment code this page cannot decode is not a bad code. It is one the regulation did not happen to name. A tool that called it invalid would be telling people their perfectly legal pallet was counterfeit, which is a worse error than saying nothing.

One asymmetry worth stating, because it is deliberate. The box on this page reads any treatment code. The site’s universal lookup only offers a pallet stamp when the code is HT or MB — because “two letters, some digits, two letters” also describes a Browning shotgun serial, and a box that guesses across every scheme on the site cannot afford to claim that one. Here you have already told us what you are holding.

The codes this page will not give you, and why

The full treatment list is in ISPM 15, published by the IPPC Secretariat. Its copyright page puts it under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 IGO licence: the work “may be copied, redistributed and adapted for non-commercial purposes”.

This site carries adverts, so that rules it out. ShareAlike would also push the IPPC’s licence onto everything here. The standard was fetched and read — ippc.int’s robots.txt says User-agent: * with an empty Disallow, which permits it — and then not reproduced, because robots.txt governs fetching and terms govern reuse. They are different questions and this site keeps them apart.

What made the page possible is that 7 CFR 319.40-3 describes the same mark independently, in words the US government wrote and nobody owns.

What the stamp does not say

There is no date in it. No year, no month, no batch. The mark certifies that the wood “has been subjected to an approved measure” — something done at the point of manufacture — and nothing about when.

It also describes a treatment, not a condition. It is a record of what the producer certified was done to the timber. It says nothing about what the pallet has carried, leaked, or stood in since, and this page cannot tell you that either.

Two fields belong to somebody else

The producer number is “a unique number assigned by the national plant protection agency of that country”. The regulation gives it no format at all, which is why its length and punctuation vary from country to country and mean nothing on their own. There is no public register of them here.

The country code is ISO 3166-1 alpha-2, and that list belongs to ISO rather than to the CFR. This page does not print a country table it has no source it may reproduce, so it names the field and stops.

That makes this the sixth source on the site to define a structure and hand part of it away, after the railway regulation, the Hallmarking Act, 47 CFR 2.926, the egg directive and 40 CFR 1060.135. The tail number remains the only one that delegates nothing.

Where the mark is, and what happens without one

“The wood packaging material must be marked in a visible location on each article, preferably on at least two opposite sides of the article, with a legible and permanent mark”

So if you cannot find it on one side, try the opposite one, and the stringers and blocks as well as the deck boards.

“An inspector at the port of first arrival may order the immediate reexport of regulated wood packaging material that is imported without the mark”

Which is worth knowing in the other direction. A pallet with no mark at all has most likely never left the country it was made in — domestic-only pallets are not required to be treated or stamped, so an absent stamp is usually a fact about where the pallet has been rather than a fault.

A note on where this came from

The regulation is the 2025 annual edition of the CFR, fetched from govinfo.gov as XML. The links above point at the eCFR, which is the version a person can navigate — but it renders in JavaScript and gives an automated reader no regulation text, so what a machine checks and what a reader opens are deliberately different.

A work of the United States government carries no copyright. ISPM 15 does, and is linked rather than copied.