[1] Session Protocol Machine (ISO/OSI-Schicht 5)
[2] SONET Physical Layer Mapping (for FDDI)
[3] Sequential Processing Machine (->"IEEE Standard Dictionary")
[4] Software Project Management (->"IEEE Standard Dictionary")
[5] Source Program Maintenance (->"IEEE Standard Dictionary")
[6] Solar Proton Monitor (->"Lexikon der Text- und Datenkommunikation")
[7] System Performance Monitor (IBM)
[8] Sample Plasma Monitor (Teil von ROMAP) {Astronomie}
[9] Spangdahlem, Germany - internationale Fughafen-Kennung