sasl_mech_list in imapd.conf ?

[Patrick Goetz]

My old Ubuntu imapd.conf includes this line:

    sasl_mech_list: PLAIN LOGIN

and sasl_mech_list is also mentioned here:
  https://cyrusimap.org/docs/cyrus-imapd/2.4.6/faq.php

However, sasl_mech_list no longer appears as an option in the imapd.conf 
man page.

Has this option been removed, or is this a bug in the man page? 
Googling for "imapd sasl_mech_list deprecated" didn't turn anything up.