diff --git a/Documentation/user-search.txt b/Documentation/user-search.txt
index 44921ad..4293fd6 100644
--- a/Documentation/user-search.txt
+++ b/Documentation/user-search.txt
@@ -377,6 +377,10 @@
 The link:http://www.brics.dk/automaton/[dk.brics.automaton library,role=external,window=_blank]
 is used for the evaluation of such patterns.
 +
+Note that the Gerrit host may not support regular expression search.
+You will then see an error dialog when using expressions starting with
+`^`.
++
 The `^` required at the beginning of the regular expression not only
 denotes a regular expression, but it also has the usual meaning of
 anchoring the match to the start of the string.  To match all Java