--- a/mercurial/help/templates.txt	Thu Sep 10 23:32:36 2015 +0900
+++ b/mercurial/help/templates.txt	Sat Sep 12 00:21:41 2015 +0900
@@ -106,6 +106,10 @@
 
    $ hg log --template "{ifcontains(rev, revset('.'), '@')}\n"
 
+- Show details of parent revisions::
+
+   $ hg log --template "{revset('parents(%d)', rev) % '{desc|firstline}\n'}"
+
 - Show only commit descriptions that start with "template"::
 
    $ hg log --template "{startswith('template', firstline(desc))}\n"