https://salsa.debian.org/release-team/britney2/-/blob/master/etc/britney.conf
Thanks. (The britney-in-general documentation giving the name of the setting was easier to find than the britney-in-Debian configuration, and I'd probably mistaken it for a conf.d directory where all the files are used.)
(I knew that message wouldn't go to you; at this stage I'd intended it as a discussion within the R team.)
