-One other transition is handled, the `indexdb` mode handles converting
-a plain text `.ikiwiki/index` file to a binary `.ikiwiki/indexdb`. In this
-mode, you should specify the srcdir of the wiki as the second parameter.
-You do not normally need to run `ikiwiki-transition indexdb`; ikiwiki will
-automatically run it as necessary.
+# indexdb
+
+The `indexdb` mode handles converting a plain text `.ikiwiki/index` file to
+a binary `.ikiwiki/indexdb`. In this mode, you should specify the srcdir of
+the wiki as the second parameter. You do not normally need to run
+`ikiwiki-transition indexdb`; ikiwiki will automatically run it as
+necessary.
+
+# hashpassword
+
+The `hashpassword` mode forces any plaintext passwords stored in the
+`.ikiwiki/userdb` file to be replaced with password hashes. (The
+Authen::Passphrase perl module is needed to do this.) In this mode, you
+should specify the srcdir of the wiki as the second parameter.
+
+If this is not done explicitly, a user's plaintext password will be
+automatically converted to a hash when a user logs in for the first time
+after upgrade to ikiwiki 2.48.