Securities, for one.
Maybe create a "Bonds" subcategory to Securities and apply the warning only there?
I'd prefer to see it applied to Securities as a whole. If we're going to add another sub-category, I'd prefer it to be HYIPs and for the Lending and Securities forums to be heavily moderated for a while so that people don't just promote their HYIPs in forums where there's no warning and don't have an incentive to mis-label their schemes.
God, more subforums. There are enough subforums already. The reason why there are so many pirate discussion topics is because there are so many different subforums.
High Yield Investment Programs = Ponzi, so just call it a Ponzi. Or better yet, stop nursing those that can't take care of themselves.
"100% return in 15 weeks to an anonymous person that won't tell me how they make the money. This is a swell idea!"