Hey, soon you can ask nbuild.io chatbot. I launched a ui preview on nbuild.io and nbuild.io/answers. I asked the chatbot your question. I received this answer:
Extra kind 0 profile fields are mention...
I validated this generated answer by hand. NIP-01 refers to kind 0 user metadata field where its content is a JSON formatted string with extra metadata fields (NIP-24) to describe the user who created the event.