HP ProCurve 6200yl Multicast And Routing Manual page 100

PIM-SM (Sparse Mode)
Terminology
4-8
RPT: See Rendezvous Point Tree.
RP-Set: A complete list of multicast-group-to-RP mappings the BSR has
learned and distributed to the C-RPs in a given PIM-SM domain. The learned
RP-set applies only to C-RPs, and not to static-RPs. (Note, however, that the
show ip pim rp-set command lists both the learned RP-set from the BSR and
any static-RPs configured on the router.)
Shortest Path Tree (SPT): The shortest path from the DR through any
intermediate PIM-SM routers leading to the PIM-SM edge router(s) for the
multicast receiver(s) requesting the traffic for a particular multicast group.
Unless the RPT is in this path, it is excluded from the SPT. (Refer to "Shortest-
Path Tree (SPT)" on page 4-10.)
SPT: See Shortest Path Tree.
Static Rendezvous Point (Static-RP). A PIM-SM router manually config­
ured as the distribution point for a multicast group or range of contiguous
groups. (Refer to "Static Rendezvous Point (Static-RP)" on page 4-17.)