I'd already covered the security point replying to another poster (https://news.ycombinator.com/item?id=14163792) but just to be clear, I'm absolutely not claiming robots.txt is a security tool. Quite the opposite, I saying following good security and design practices renders the robots.txt file obsolete.
Your point about sitemaps helps illustrate that point of mine because having a decent sitemap mitigates the need for Allow lines in robots.txt. It's another feature of the web where robots.txt isn't well equipped to handle and thus there have been other, better, tools built to highlight pages of interest to search engines.
Your point about sitemaps helps illustrate that point of mine because having a decent sitemap mitigates the need for Allow lines in robots.txt. It's another feature of the web where robots.txt isn't well equipped to handle and thus there have been other, better, tools built to highlight pages of interest to search engines.