Are we allowed to talk about Bitcoin layer 2 technologies on this sub?

I tried asking a question about the lightning network and moderators took it down.

If we aren't allowed to talk about that stuff here, do you have any recommendations? Or is it just certain aspects of the lightning network we cant talk about? I was also asking about sidechains such as RSK and Liquid. Is sidechain talk banned?

I just had a question about an article I found on "cointelegraph". Was the post removed because I linked to the article when I asked about it?

I tried the "lightning network" sub, but it seems to be dead.

I'm just trying to ask a simple question, so if someone could tell me a good sub to ask it on, or at least explain how to format posts here so that they wont get removed, I would really appreciate it.