Discovery Service:
http://code.google.com/apis/discovery/
http://code.google.com/apis/discovery/v1/reference.html

The "type" key:
http://tools.ietf.org/html/draft-zyp-json-schema-03#section-5.1

The "format" key:
http://tools.ietf.org/html/draft-zyp-json-schema-03#section-5.23
http://code.google.com/apis/discovery/v1/reference.html#parameter-format-summary

Google JSON format docs:
http://google-styleguide.googlecode.com/svn/trunk/jsoncstyleguide.xml