No problem. I wish they'd make these things easier to find. Here's the spec, it should answer all your questions. If not, feel free to ask more.

https://spec.narrative.org/docs

There's also a community support site where you can ask questions, offer suggestions, and notify staff of issues. You have to sign up for a separate account because it's not a part of the main site.

Finally, one of the users put together this nifty guide. It's a pretty handy collection of posts by other Narrators on how to make the best use of the site, and tips for doing certain things. The best part is these are all by other users so you're learning from the grass roots.