--- a/src/Doc/System/Phabricator.thy Sat Jan 11 15:04:43 2020 +0100
+++ b/src/Doc/System/Phabricator.thy Sat Jan 11 16:22:17 2020 +0100
@@ -309,7 +309,8 @@
The Phabricator developers publish a new version approx.\ every 1--4 weeks:
see also \<^url>\<open>https://secure.phabricator.com/w/changelog\<close>. There is no need to
follow such frequent updates on the spot, but it is a good idea to upgrade
- occasionally --- after dump and/or backup (\secref{sec:phabricator-backup}).
+ occasionally --- with the usual care to avoid breaking a production system
+ (see also \secref{sec:phabricator-backup} for database dump and backup).
The Isabelle/Phabricator setup provides a convenience tool to upgrade all
installations uniformly: