S (from S to S)
S1 (from S1909/A2840 to S1G reactor)
S3 (from S3G reactor to S3G reactor)
S4 (from S4C to S4C)
S5 (from S5G reactor to S5G reactor)
S7 (from S7G reactor to S7G reactor)
S_ (from S-100 bus to Süpplingenburg)
Sa (from SA to Sazerac)
Sb (from SB to SBus)
Sc (from SC to Scythia)
Sd (from SD to SDXF)
Se (from Sea to Seyyed Razi)
Sf (from SF to Sfumato)
Sg (from SG to Sgt. Slaughter)
Sh (from SH3 domain to Shyness)
Si (from SI to Sizzle cymbal)
Sj (from SJ to Sjofn)
Sk (from SK to Skywriting)
Sl (from SL to Sly Stone)
Sm (from SM to Smyth County, Virginia)
Sn (from SN1 reaction to Snydertown, Pennsylvania)
So (from So-Called Chaos (album) to Sozopol)
Sp (from SP to Spyware)
Sq (from SQL to Squonk)
Sr (from SR to SRY)
Ss (from SS to SST Records)
St (from ST to Styx (mythology))
Su (from SU-100 to Suzy Parker)
Sv (from Sv to SVT2)
Sw (from SW to SWTPC)
Sx (from SX to SXSW)
Sy (from Syagrius to Syzygy)
Sz (from Szczecin to Szuma Chien)