I am confused that why google add following code in blogger robot.txt

User-agent: *
Disallow: /search
Allow: /

If I am not wrong, Disallow: /Search means your blog will be not visible in search results?

Complete robot.txt is as under

User-agent: *
Disallow: /search
Allow: /

And secondly, when I add the custom robot.txt , it get saved but don't take effect practically. I check it by visiting
http://www.mybloggerblog.com/robots.txt