[master] explain [placeholder]

diff --git a/README b/README
index 713ac6dfbb772e55e222e8591284c3569eae5478..e504853defbb223cecbf3b974855a7be6a03f24d 100644 (file)
--- a/README
+++ b/README
@@ -416,6 +416,11 @@ Change Log
 
           [doc]          Documentation
 
+          [placeholder]  Used in the master development branch to
+                         reserve change numbers for use in other
+                         branches, e.g. when fixing a bug that only
+                         exists in older releases
+
        In general, [func] and [experimental] tags will only appear
        in new-feature releases (i.e., those with version numbers
        ending in zero).  Some new functionality may be backported to