diff --git a/doc/4-wildcard-repositories.mkd b/doc/4-wildcard-repositories.mkd
index 7e54a1c..1feac40 100644
--- a/doc/4-wildcard-repositories.mkd
+++ b/doc/4-wildcard-repositories.mkd
@@ -8,6 +8,14 @@ This branch contains features that are likely to be much more brittle than the
 R and RW permissions to other users to collaborate, all these are possible.
 And any of these could have a bug in it.
 
+"Brittle" also means some features in "master" may not work here.  For
+example, you cannot specify gitconfig values for a wildcard repo; it only
+works for actual repos.
+
+There may be other such missing features.  Sometimes it's just not possible to
+make it work.  Or it may be cumbersome enough that unless there are *no*
+workarounds I may not have the time to code it right away.
+
 ----
 
 In this document: