diff -r 3973b1dc3ee3 -r 4077d6222cf1 mercurial/configitems.py
--- a/mercurial/configitems.py	Tue Mar 14 05:30:34 2023 +0100
+++ b/mercurial/configitems.py	Sat Apr 13 01:17:56 2019 +0200
@@ -1244,6 +1244,11 @@
 )
 coreconfigitem(
     b'experimental',
+    b'server.allow-hidden-access',
+    default=list,
+)
+coreconfigitem(
+    b'experimental',
     b'server.filesdata.recommended-batch-size',
     default=50000,
 )