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Technically that could be done in your robots.txt file but I wouldn't recommend that if you want Google to crawl them too.  I'm not sure if Rogerbot can do that.  Sorry I couldn't be more help. If you don't get one of the staffers on here in the next few days, I would send a ticket to them for clarification. If you decide to go with robots.txt here is a resource from Google on implementing and testing it.  https://support.google.com/webmasters/answer/156449?hl=en