I’m not sure Google has specific guidelines for software-only distributions since they don’t really exist outside of custom AOSP distributions. All major OEMs ship hardware along with their own Android skins. Either way, if the guidelines don’t apply, then the default would be GrapheneOS having no access to use Google’s trademarks.
Custom ROMs can refer to themselves as an “Android distribution” or “Android operating system” according to the word mark guidelines.
Android may be used as a descriptor in text, as long as it is followed by a proper generic term and is not the name of your product, app, or service. Think of “Android” as a term used in place of “the Android platform.”
Not that it particularly matters, because like I said the way we describe things on the site does not have to be correlated with the way developers market themselves at all.
Alright, I clearly misunderstood the guidelines, thanks for clarifying.