X-OAuth-Scopes:

[1] OAuth | Slack (Slack 著, 2015-03-05 16:07:15 +09:00 版) <https://api.slack.com/docs/oauth>

X-OAuth-Scopes lists the scopes your token has authorized.

[2] OAuth | GitHub API (2015-03-05 18:02:01 +09:00 版) <https://developer.github.com/v3/oauth/#scopes>

[3] Authenticating with the Meetup API - Meetup (2015-03-06 09:01:07 +09:00 版) <http://www.meetup.com/meetup_api/auth/>

Note, when making a request you should be able to see which scopes have been enabled and are required using in the following headers
X-OAuth-Scopes: basic, messaging
X-Accepted-OAuth-Scopes: basic, messaging