Sianel Pedwar Cymru (the Welsh language television channel)
SA
Salvation Army / Sex appeal / South Australia / South Australian / South America / South Africa / Society of Arts/ Small arms (military)/ Societe anonyme (French) = Limited Liability Comapany / Society of Antiquaries (SAL of London or SAS of Scotland) / Sturmabteilung (German) = Storm Section (a Nazi terrorist militia) / Sino-auricular or sino-atrial (Medicine)
sa
Secundum artem (Latin) = according to art / Sine anno (Latin) = without date / without year
SAA
Small arm(s) ammunition
SAARC
(acronym) — South Asian Association for Regional Co-operation
SABC
South African Broadcasting Corporation
SAC
Scottish Arts Council / Special Area of Conservation / Strategic Air Command (US) / Senior Aircraftman (UK)
(abbreviation & acronym) Stock Automatic Execution Facility (see also SEAQ)
SAIL
(acronym) Steel Authority of India Limited
Sb
Stibium (Latin) = Antimony
Sb.
Substantive
SBA
Small Business Administration
S-Bahn
(Stadt) Schnellbahn (urban) (German) = fast railway (fast urban railway system in Germany)
SBF
Single black female (used in personal advertisements)
SBM
Single black male (personal advertisements) / Single buoy mooring
SBN
Standard book number (now ISBN = International Standard Book Number)
SBR
Styrene-butadiene rubber
SBI
State Bank of India
SBS
Sick building syndrome (also TBS = Tight building syndrome) / Special Boat Service
SC
Supreme Court / Scheduled Caste
SD
Standard Deviation (statistics) / South Dakota (in official postal use) / Sequence Data
SDF
Social Democratic Federation
SDI
Strategic Defense Initiative
SDLP
Social Democratic and Labour Party (UK)
SDO
Sub-divisional Officer (military)
SDP
Social Democratic Party (UK – history)
SDR
Special Drawing Right (from IMF – the International Monetary Fund)
SE
south-east / south-eastern; chemical symbol for Selenium
SEA
(both abbreviation & acronym) – Single European Act
SEAL
Sea Air Land (team) (an elite force in the US Navy)
SEATO
(acronym) South East Asia Treaty Organization (now defunct)
SEC
Securities and Exchange Commission
Sec.
Secretary
SECAM
(acronym) Sequentiel couleru a memoire (French) = a broadcasting system for colour television
SF
Science Fiction / Signal frequency / Sinn Fein / San Francisco / Swedish Finland (from Finnish Suomi) = Finland (IVR)
sf
Sforzando (music)
SFA
Scottish Football Association / Sweet Fanny Adams (slang) = nothing at all / Securities and Futures Authority (UK) (now replaced by FSA = Financial Services Authority)
SFAS
Statement of Financial Accounting Standards
SFO
Serious Fraud Office (UK)
SFX
Special Effects
sfx
Suffix
sfz
Sforzando (music)
SG
Senior grade (US) / Solicitor General (Law) / Specific gravity
Sg
Seaborgium (Chemistry)
sgd
Signed
SGHWR
Steam-generating heavy water reactor
SGML
Standard Generalized Mark-up Language (coding for printed applications)
SGP
Singapore (IVR = International Vehicle Registration)
Sgt
Sergeant
s/h
Shorthand
sh.
Shilling(s)
SHA
(abbreviation & acronym) Strategic Health Authority
SHAEF
Supreme Headquarters Allied Expeditionary Force
SI
Systeme International (French) the international system of units of measurement / Statutory instrument (Law) / South Island (of NZ) / (Order of) the Star of India
Si
Silicon (chemical element)
SIB
Special Investigations Branch / Securities and Investments Board (now known as FSA = Financial Services Authority)
sib
Sibilant
SIDS/Sids
Sudden infant death syndrome = cot death
SIFI
(acronym) Systematically Important Financial Institution (US)
SIG
Special interest group (computing) (a type of news group)