The Sandbox currently says:
When you think your challenge is ready for the public, go ahead and post it, and replace the post here with a link to the challenge and delete the sandbox post.
(Emphasis original.)
These days, however, I see a lot of sandbox posts which are edited down to a link but are not deleted. I asked about it in chat and got a couple of responses but nothing definitive. Should we delete sandbox posts after posting them to main? Or should we remove that clause from the Sandbox instructions?