The number of token windows in each direction that should be valid. This tells OATH to accept tokens for a range of effectively ((1 + 2 * $wgOATHAuthWindowRadius) * 30) seconds. This range of valid windows is centered around the current time. The purpose of this configuration variable is to account for differences between the user's clock and the server's clock. However, it is recommended to keep it as low as possible.
The database domain. Only used in a multi-database environment.
The base OATHAuth secret for this wiki from which all encryption keys are derived. If false, the value of $wgSecretKey is used.
The prefix used for the OATHAuth user account name and the issuer used for the account. If false, the value of $wgSitename is used.
In the event that a user both loses their token generator AND the recovery tokens; two-factor authentication may be removed from the user by deleting their row from the oathauth_users database table. A sysadmin with shell access may type on a command line cd /path/to/mediawiki/extensions/OATHAuth/maintenance/ and then execute php disableOATHAuthForUser.php "<username>" where <username> is the user to have 2FA disabled to have it disabled.
This extension is being used on one or more Wikimedia projects. This probably means that the extension is stable and works well enough to be used by such high-traffic websites. Look for this extension's name in Wikimedia's CommonSettings.php and InitialiseSettings.php configuration files to see where it's installed. A full list of the extensions installed on a particular wiki can be seen on the wiki's Special:Version page.