> If I can't post my FOSS to the linux subreddit then what in the world am I allowed to post?

There is not enough information in your comment to judge correctly, but I would like to point out that it's not black and white.

You know what I hate about Hacker News lately? The green accounts that show up, post a link to their product (sometimes even making it to the front page), do not reply to comments, and exist only to keep spamming their own links. I also saw a post gain 16 upvotes even though they forgot to post the actual content.

If you regularly contribute to the linux subreddit, participate in discussions, and post interesting links from non-affiliated sources then yes, being deleted for "self promotion" sounds unfair. But if you only go there to promote your project then I'd also side with the mods.

The thing is that most of these submissions go nowhere on HN. So, what is actually the problem? Lousy submissions don’t get upvoted and no one is bothered. The problem on Reddit is that even legitimate submissions are taken down by nay-sayers despite being positive and getting legitimate upvotes, while submissions of links that lead to big companies’ websites don’t get nearly the same level of scrutiny.

It seems the best way these days is to get creative - Write a blog post that is interesting to the target audience and mention your product as an aside.

Exactly like this HN submission did.

Well, that largely depends on the subreddit and the context.

Always read the wiki before posting. When in doubt, ask moderators if they're OK with self-promotion.

Self-promotion doesn't mean you spam links left and right. Try to provide value first, and maybe at the end of your post/comment, link to your website.

My open source repo was inspired by conversations in the subreddit, and open source software doesn't do much besides provide value.