This will probably be a work in progress as the community grows, but I thought I'd throw out some initial interpretations. The system comes with these status categories, and they aren't perfect, so I'm improvising a bit. Very open to suggestions about suggestions!
I've moved the suggestion to the developers' To-Do list. This means they see it every day, and have it in mind when they're working on other features. That helps them to determine the best way to build the suggested feature. I probably won't be able to give you an estimated date, but if it's on the To-Do list, it's probably coming up soon.
A developer has taken it off the To-Do list and moved it to their Doing list. Keep in mind they're trying to help you solve a particular problem, and the final solution might not be exactly as described. If they recommend something that seems very different from your original intent, I'll come back here for more conversation.
This isn't necessarily a bad thing, though it sounds negative. I'm going to use this as a status for things we're considering but aren't ready to add to Planned. We might need more feedback from users, or there might be other components that need to be completed first. If it's really huge, it might just take time.
Your suggestion has been implemented and rolled into production in the application. Keep in mind, this won't always mean we built it exactly as you described. In some cases we need to take small steps. If we implement a piece of it but there's still good stuff we could add from the same suggestion, I'll mark it Implemented, and start a new suggestion for the remaining components. (That's why it helps to create small suggestions.)
These are suggestions we aren't able to implement. Our developers are pretty amazing, so we hope we can implement a lot of suggestions. There are a few reasons a suggestion might not be taken. I think one of the primary reasons might be if it's a suggestion that would add a large burden of complexity for users. We are committed to simplifying your work, and keep that in mind as we review suggestions. The other main reason would be if it's a feature that is very specific to your institution and won't benefit others. In any case, we won't reject suggestions without conversations first!