diff -r b7a0efb3c370 -r 13a6dd952ffe mercurial/help/config.txt
--- a/mercurial/help/config.txt	Mon Feb 04 18:14:03 2019 +0300
+++ b/mercurial/help/config.txt	Mon Feb 04 20:35:21 2019 +0300
@@ -857,6 +857,16 @@
 
     Enabled by default.
 
+``sparse-revlog``
+    Enable or disable the ``sparse-revlog`` delta strategy. This format improves
+    delta re-use inside revlog. For very branchy repositories, it results in a
+    smaller store. For repositories with many revisions, it also helps
+    performance (by using shortened delta chains.)
+
+    Repositories with this on-disk format require Mercurial version 4.7
+
+    Enabled by default.
+
 ``graph``
 ---------