User-agent: Googlebot

Disallow: /login?to=*
Disallow: /register?to=*
Disallow: /ask
Disallow: /user
Disallow: /submit?*
Disallow: /video?*
Disallow: /?*

User-agent: Yahoo-slurp
Disallow: /login?to=*
Disallow: /register?to=*
Disallow: /ask
Disallow: /user
Disallow: /submit?*
Disallow: /video?*
Disallow: /?*

User-Agent: bingbot
Disallow: /login?to=*
Disallow: /register?to=*
Disallow: /ask
Disallow: /user
Disallow: /submit?*
Disallow: /video?*
Disallow: /?*

User-Agent: Baiduspider
Disallow: /login?to=*
Disallow: /register?to=*
Disallow: /ask
Disallow: /user
Disallow: /submit?*
Disallow: /video?*
Disallow: /?*

User-agent: *
Disallow: /