diff --git a/orte/tools/orterun/orterun.1 b/orte/tools/orterun/orterun.1
index 0fa22a57d6..4e1e3d8f05 100644
--- a/orte/tools/orterun/orterun.1
+++ b/orte/tools/orterun/orterun.1
@@ -236,6 +236,11 @@ Suppress informative messages from orterun during application execution.
 .
 .
 .TP
+.B -rf \f |--rankfile <arg0>\fP.
+Provide a rankfile file.
+.
+.
+.TP
 .B --tmpdir \fR<dir>\fP
 Set the root for the session directory tree for mpirun only.
 .
@@ -519,6 +524,27 @@ on host a. And runs one copy of the executable
 on hosts b and c.
 .
 .
+.SS Specifying Ranks
+.
+Rankfile came to provide Open MPI a file with the location of each MPI_COMM_WORLD rank. The syntax of the rankfile as follows:
+ rank i=host_j slot=x
+
+    \fBshell$\fP cat my-rankfile
+    rank 1=host1 slot=1:0,1
+    rank 0=host2 slot=0:*
+    rank 2=host4 slot=1-2
+    rank 3=host3 slot=0:1,1:0-2
+
+    \fBshell$\fP mpirun --hostfile my-hostfile -np 4 --rankfile my-rankfile a.out
+    
+This means that
+ a. rank 1 will run on host1 bounded to socket1:core0 and socket1:core1
+ b. rank 0 will run on host2 bounded to any core on socket0
+ c. rank 2 will run on host4 bounded to CPU#1 and CPU#2
+ d. rank 3 will run on host3 bounded to socket0:core1 and socket1:core0, socket1:core1, socket1:core2
+. 
+.
+.
 .SS Providing cartofile
 .
 The cartofile suplies an information of the the host structure and connection among the host components i.e memory nodes,CPUs, Ethernet and inifiniband ports. The information stored as a graph in the cartofile. This graph contains the names and types of EDGEs, connecting BRANCHes and distance among them. See the fallowing example of the cartofile:
diff --git a/orte/tools/orterun/orterun.c b/orte/tools/orterun/orterun.c
index f6caca1604..09578c3fef 100644
--- a/orte/tools/orterun/orterun.c
+++ b/orte/tools/orterun/orterun.c
@@ -199,6 +199,10 @@ static opal_cmd_line_init_t cmd_line_init[] = {
       NULL, OPAL_CMD_LINE_TYPE_STRING,
       "Provide a cartography file" },
 
+    { "rmaps_rank", "file", "path", '\0', "rf", "rankfile", 1,
+      NULL, OPAL_CMD_LINE_TYPE_STRING,
+      "Provide a rankfile file" },
+
     /* Export environment variables; potentially used multiple times,
        so it does not make sense to set into a variable */
     { NULL, NULL, NULL, 'x', NULL, NULL, 1,