diff --git a/init/do_mounts.c b/init/do_mounts.c
index a51cddc2ff8c..8e5addc45874 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -197,6 +197,8 @@ static dev_t devt_from_partuuid(const char *uuid_str)
  *	   is a zero-filled hex representation of the 1-based partition number.
  *	7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to
  *	   a partition with a known unique id.
+ *	8) <major>:<minor> major and minor number of the device separated by
+ *	   a colon.
  *
  *	If name doesn't have fall into the categories above, we return (0,0).
  *	block_class is used to check if something is a disk name. If the disk