diff --git a/src/communicator/comm.c b/src/communicator/comm.c
index 646cab925b..fbc74cf384 100644
--- a/src/communicator/comm.c
+++ b/src/communicator/comm.c
@@ -599,8 +599,6 @@ int ompi_comm_set_name (ompi_communicator_t *comm, char *name )
  * 2. an inter-bcast from rank 0 in remote_group.
  */
 
-#define OMPI_COMM_ALLGATHER_TAG 31078
-
 static int ompi_comm_allgather_emulate_intra( void *inbuf, int incount, 
                                               MPI_Datatype intype, void* outbuf,
                                               int outcount, MPI_Datatype outtype,
diff --git a/src/communicator/comm_cid.c b/src/communicator/comm_cid.c
index 0f4d339196..3ed22b2384 100644
--- a/src/communicator/comm_cid.c
+++ b/src/communicator/comm_cid.c
@@ -19,7 +19,6 @@
 #include "mca/coll/base/base.h"
 #include "mca/oob/oob.h"
 
-#define OMPI_COLL_TAG_ALLREDUCE 31000
 #define OMPI_MAX_COMM 32768
 
 #if defined(c_plusplus) || defined(__cplusplus)
@@ -424,13 +423,13 @@ static int ompi_comm_allreduce_inter ( int *inbuf, int *outbuf,
         /* local leader exchange their data and determine the overall result
            for both groups */
         rc = mca_pml.pml_irecv (outbuf, count, MPI_INT, 0, 
-                                OMPI_COLL_TAG_ALLREDUCE
+                                OMPI_COMM_ALLREDUCE_TAG
                                 , intercomm, &req );
         if ( OMPI_SUCCESS != rc ) {
             goto exit;
         }
         rc = mca_pml.pml_send (tmpbuf, count, MPI_INT, 0,
-                               OMPI_COLL_TAG_ALLREDUCE, 
+                               OMPI_COMM_ALLREDUCE_TAG, 
                                MCA_PML_BASE_SEND_STANDARD, intercomm );
         if ( OMPI_SUCCESS != rc ) {
             goto exit;
@@ -529,13 +528,13 @@ static int ompi_comm_allreduce_intra_bridge (int *inbuf, int *outbuf,
         MPI_Request req;
         
         rc = mca_pml.pml_irecv ( outbuf, count, MPI_INT, remote_leader,
-                                 OMPI_COLL_TAG_ALLREDUCE, 
+                                 OMPI_COMM_ALLREDUCE_TAG, 
                                  bcomm, &req );
         if ( OMPI_SUCCESS != rc ) {
             goto exit;       
         }
         rc = mca_pml.pml_send (tmpbuf, count, MPI_INT, remote_leader, 
-                               OMPI_COLL_TAG_ALLREDUCE,
+                               OMPI_COMM_ALLREDUCE_TAG,
                                MCA_PML_BASE_SEND_STANDARD,  bcomm );
         if ( OMPI_SUCCESS != rc ) {
             goto exit;
diff --git a/src/communicator/comm_dyn.c b/src/communicator/comm_dyn.c
index fac088f47b..bc1a7b39d0 100644
--- a/src/communicator/comm_dyn.c
+++ b/src/communicator/comm_dyn.c
@@ -489,7 +489,6 @@ int ompi_comm_dyn_finalize (void)
 /**********************************************************************/
 /**********************************************************************/
 /**********************************************************************/
-#define COMM_COLL_BASE_TAG_BARRIER 30303
 
 ompi_comm_disconnect_obj *ompi_comm_disconnect_init ( ompi_communicator_t *comm)
 {
@@ -520,7 +519,7 @@ ompi_comm_disconnect_obj *ompi_comm_disconnect_init ( ompi_communicator_t *comm)
        the object, since we are sending zero size messages anyway. */
     for ( i=0; i < obj->size; i++ ) {
 	ret = mca_pml.pml_irecv (&(obj->buf), 0, MPI_INT, i,
-				 COMM_COLL_BASE_TAG_BARRIER, comm, 
+				 OMPI_COMM_BARRIER_TAG, comm, 
 				 &(obj->reqs[2*i]));
 				 
 	if ( OMPI_SUCCESS != ret ) {
@@ -530,7 +529,7 @@ ompi_comm_disconnect_obj *ompi_comm_disconnect_init ( ompi_communicator_t *comm)
 	}
 
 	ret = mca_pml.pml_isend (&(obj->buf), 0, MPI_INT, i,
-				 COMM_COLL_BASE_TAG_BARRIER, 
+				 OMPI_COMM_BARRIER_TAG, 
 				 MCA_PML_BASE_SEND_STANDARD,
 				 comm, &(obj->reqs[2*i+1]));
 				 
diff --git a/src/communicator/communicator.h b/src/communicator/communicator.h
index b16333c987..4b74f1215d 100644
--- a/src/communicator/communicator.h
+++ b/src/communicator/communicator.h
@@ -46,10 +46,16 @@ OMPI_DECLSPEC extern ompi_class_t ompi_communicator_t_class;
 #define OMPI_COMM_SET_DYNAMIC(comm) ((comm)->c_flags |= OMPI_COMM_DYNAMIC)
 
 
-#define OMPI_COMM_HAVETO_DISCONNECT ((comm)->c_flags & OMPI_COMM_DISCONNECT)
-/* a special tag to recognize an MPI_Comm_join in the comm_connect_accept
-   routine. */
-#define OMPI_COMM_JOIN_TAG  32000
+/* a set of special tags: */
+
+/*  to recognize an MPI_Comm_join in the comm_connect_accept routine. */
+#define OMPI_COMM_JOIN_TAG  -32000
+
+#define OMPI_COMM_ALLGATHER_TAG -31078
+#define OMPI_COMM_BARRIER_TAG   -31079
+#define OMPI_COMM_ALLREDUCE_TAG -31080
+
+
 
 /** 
  * Modes reqquired for accquiring the new comm-id.