It's completely standard practice now, but since when? It didn't start this way because open source projects didn't used to be so big that they had foundations

It's completely standard practice now, but since when? It didn't start this way because open source projects didn't used to be so big that they had foundations and trademarks. Furthermore, I think there's a bit of nuance that people continue to miss: I'm not referring to having trademark rules. I am familiar with Linux and Mozilla, arguably the earliest "open source" organizations to deal with trademarks and have trademark policies. What I'm referring to more specifically is what Go and Rust are doing for events: they seem to be applying additional rules for events that use the trademark in a way that does not imply affiliation. I think this is something that has not generally been the case for open source trademarks.