[1] OAuth 1.0 API Reference - Google Accounts Authentication and Authorization — Google Developers (2014-12-05 11:52:26 +09:00 版) https://developers.google.com/accounts/docs/OAuth_ref#GetAuth

hd (optional) String value identifying a particular hosted domain account to be accessed (for example, 'mycollege.edu'). Use "default" to specify a regular Google account ('username@gmail.com'). This is a Google-specific parameter.