This is the first thing that came to mind for me too. However, I am distinguishing this particular case (e.g. enforcing that you don't use trademarks in a way t

This is the first thing that came to mind for me too. However, I am distinguishing this particular case (e.g. enforcing that you don't use trademarks in a way that would imply something is official) with the Rust/Go/Python trademark policies (e.g. enforcing a set of rules when using a trademark to refer to something in a clearly unofficial context.)