Last modified: 2013-11-27 00:50:11 UTC
list=betafeatures, provides the name of the preference options and counts of how many users are using them.
Change 97859 had a related patch set uploaded by Legoktm: API module: list=betafeatures https://gerrit.wikimedia.org/r/97859
Change 97859 merged by jenkins-bot: API module: list=betafeatures https://gerrit.wikimedia.org/r/97859
After some confusion with the param names.