[MSDN Library April 2000] SPI Semantics for Joining Multipoint Leaves (47.7930707166588%)
MSDN Library - April 2000 > Platform SDK > Networking and Directory Services > Windows Sockets Version 2 > Windows Sockets Version 2 SPI > Overviews > Windows Sockets 2 Transport Provider Requirements > Protocol-Independent Multicast and Multipoint in the SPI