No worries, we don't actually have any set rules for when we do past prompts - usually it is for a big events like the hundreds when we offer prizes for the people who write the most drabbles but it can depend on what else is going on in the fandom. I don't expect to do another one for a while since it wasn't that long ago since we did the last one. Maybe challenge 250 but it'll depend what time of year that falls.