Company threatened Ethereum standard author over the name "Diamond Standard"

I'm the author of Ethereum’s "ERC-2535 Diamonds" standard, a modular smart contract standard that has been used in the ecosystem for years.

In 2020, shortly after publishing the standard, I received a trademark infringement threat from a company called Diamond Standard Inc. They claimed I was infringing on their trademark simply by naming the standard “ERC-2535 Diamond Standard.” Because of this, I renamed it to “ERC-2535 Diamonds.”

At the time, I didn’t think an Ethereum smart contract standard could realistically infringe on a trademark — it isn’t a product or service. But the threat was serious enough that I complied, mostly to avoid an unnecessary legal battle.

I’ve now gone public with the story and released the redacted legal letter I received (link below). I’m also considering proposing a new smart contract standard that would be a simpler version of ERC-2535, and I am wondering whether the name “Diamond Standard” would still present any legal issues today.

I’d really appreciate informed opinions from people familiar with trademark law, intellectual property, or open-source governance. In particular:

Can the name of a technical standard infringe a trademark?

Does trademark law apply when there is no commercial product?

Does their original claim seem valid under U.S. trademark law?

Are there precedents involving naming of technical or open-source standards?

Here is the redacted legal letter and my post explaining the backstory: https://x.com/mudgen/status/1997650412090826959

Thanks in advance for any insights.

— Nick Mudge