robots.txt

User-agent: *
# Let crawlers index Release Notes but not old docs
Allow:    /1.8/readme/changes/rel1.8.html
Disallow: /1.8/
Allow:    /2.0/readme/changes/rel2.0.html
Disallow: /2.0/
Allow:    /2.1/release-notes/
Disallow: /2.1/
Allow:    /2.2/release-notes/
Disallow: /2.2/
Allow:    /2.3/release-notes/
Disallow: /2.3/
Allow:    /2.4/release-notes/
Disallow: /2.4/
Allow:    /2.5/release-notes/
Disallow: /2.5/
Allow:    /3.0/release-notes/
Disallow: /3.0/
Allow:    /3.1/release-notes/
Disallow: /3.1/
Allow:    /3.2/release-notes/
Disallow: /3.2/
Allow:    /3.3/release-notes/
Disallow: /3.3/
Allow:    /3.4/release-notes/
Disallow: /3.4/
Allow:    /3.5/release-notes/
Disallow: /3.5/
Allow:    /3.6/release-notes/
Disallow: /3.6/
Allow:    /3.7/release-notes/
Disallow: /3.7/
Allow:    /4.0/release-notes/
Disallow: /4.0/
Allow:    /4.1/release-notes/
Disallow: /4.1/
Allow:    /4.2/release-notes/
Disallow: /4.2/