-It can be required by the authentication realm, either via 'TOTP' or
-'YubiKey OTP'. In this case a newly created user needs their keys added
-immediately as there is no way to log in without the second factor. In the case
-of 'TOTP' a user can also change the 'TOTP' later on provided they can log in
-first.
+It can be required by the authentication realm, either via 'TOTP'
+(Time-based One-Time Password) or 'YubiKey OTP'. In this case a newly
+created user needs their keys added immediately as there is no way to
+log in without the second factor. In the case of 'TOTP', users can
+also change the 'TOTP' later on, provided they can log in first.