SA        Selective Availability

SAA       Systems Application Architecture [IBM]

SABRE     Semi-Automatic Business Research Environment

SAC       Single Attachment Concentrator

SACD     Super Audio Compact Disk

SACL      System Access Control List

SADL      Synchronous Data Link Control [Racal-Vadic]

SAINT   * Symbolic Automatic Integrator

SAL       Shift Arithmetic Left + Spatial Aggregation Language

SAM       Serial Access Memory + Sequential Access Method +

          Security Accounts Manager [Microsoft] +

          Single Application Mode [Microsoft]

SAML      Security Assertion Markup Language

SAN       Storage/System Area Network

SANE      Standard Apple Numeric Environment

SAP       Second Audio Program + Service Access Point [DEC]

              Session Announcement Protocol +

          Service Advertising Protocol +

        * Symbolic Assembly Program +

          Systems, Applications and Products (company)

SAPI      Speech Application Program Interface [Microsoft]

SAR       Segmentation and Reassembly +

          Shift Arithmetic Right + Specific Absorption Rate

          Successive Approximation Register +

          Synthetic Aperture Radar

SARG      Search Argument

SAS       Sales Accounting System + Single Attached Station +

          Single Audio System + Statistical Analysis System

SASI      Shugart Associates System Interface (SCSI originated

          from SASI)

SATA      Serial Advanced Technology Attachment

SATAN     Security Administrator Tool for Analyzing Networks

.SAV      Saved (file name extension)

SAVDM     Single Application VDM

SAX       Simple API for XML

SB        Sound Blaster [Creative Labs] + Sound Board

SBA       Scene Balance Algorithms [Kodak] +

              Service Based Architecture

SBAS      Satellite Based Augmentation System

SBB       Subtract With Borrow

SBC       Single-Board Computer

SBCS      Single-Byte Character Set

SBI       Sound Blaster Instrument

.SBR      Source Browser (file name extension) [Borland]

SBS        Small Business Server +

          Smart Battery Specification [Duracell/Intel]

.SC       Script (file name extension)

SCA       Scalable Computing Architecture [HP]

SCADA     Supervisory Control and Data Acquisition

SCAM      SCSI Configuration Automatically

SCAS      Scan String

SCB       Subsystem Control Block [IBM]

SCC       Serial Communications Controllers +

          Serial Controller Chip +

          Synchronous Channel Check [IBM]

SCCP      Simple Conference Control Protocol

SCCS      Source Code Control System

SCD       Standard Color Display

S-CDMA    Synchronous Code-Division Multiple Access

SCF       System Control Facility

SCI       Scalable Coherent Interface +

          Serial Communications Interface

SCI.      Science [USENET Newsgroup Category]

SCIL      Serial Control Interface Logic

SCLM      Software Configuration and Library Management [IBM]

SCM       Service Control Manager + ScreenCam Format [Lotus] +

          Software Configuration Management + Station Class Mark

SCO       Santa Cruz Operation (Software Company) +

              Synchronous Connection-Oriented (link)

SCOPE     Simple Communications Programming Environment

          [Hayes]

SCP       Save Cursor Position + Subsystem Control Port +

          System Control Program

SCR       Silicon Controlled Rectifier

.SCR      Script (file name extension)

SCRAM   Software Configuration, Release and Management

SCRN      Screen (video display)

SCRS      Scalable Cluster of RISC Systems

SCSA      Signal Computing System Architecture [Dialogic]

SCSI      Small Computer Systems Interface

SCTP      Stream Control Transmission Protocol

SD        Send Data + Super Density

SDA       Software Delivery Agent [IBM] + Software Disk Array +

              Source Data Automation + System Display Architecture [Digital]

SDAM      Single DOS Application Mode

SDB       Symbolic Debugger [Unix]

SDD       Software Description Database [Internet] +

          Subscriber Data Document +

          System Distribution Directory

SDF       Space Delimited File + Space Delimited Format

.SDF      Standard Data Format (file name extension)

SDH       Synchronous Digital Hierarchy

SDI       Selective Dissemination of Information +

          Single Document Interface +

          Software Development Interface [Mosaic]

SDK       Software Development Kit [Microsoft]

SDL       Specification and Description Language

SDLC      Synchronous Data Link Control (protocol)

SDM       System Development Multitasking

SDMI      Secure Digital Music Initiative/Interface

SDMMC   Secure Digital Multi Media Card

SDMS      SCSI Device Management System [NCR]

SDN       Software Defined Network [AT&T]

SDNS      Secure Data Network Service

SDR       Streaming Data Request

SDRAM     Synchronous DRAM

SD-ROM    Super Density ROM

SDS       Sysops Distribution System

SDSL      (See DSL)

SD_STB    Streaming Data Strobe [IBM]

SDTV      Standard Definition Television

SDV       Switched Digital Video [AT&T]

SDX       Storage Data Acceleration

SDXF      Structured Data Exchange Format

SEA       Standard Extended Attribute [OS/2]

.SEA      Self Extracting Archive (file name extension) [Macintosh]

SEAC    * Name of first computer to use transistors, built by

          (National Bureau of) Standards Eastern Automatic

          Calculator (Also see SWAC)

SEAL      Segmentation and Reassembly Layer (protocol) +

          Screening External Access Link [Digital-DEC]

SEC       Single Error Correction

SECAM     Sequentiel Couleur Avec Memoire

          (Sequential Color With Memory)

SECC      Single Edge Contact Cartridge

SED       Stream Editor + Stream-Oriented Editor

SEG       Segment

SEH       Structured Exception Handling

SEL       Select

SEM       Scanning Electron Microscope +

          Standard Electronic Module +

          Strategic Enterprise Management [SAP]

SEPP      Secure Encryption Payment Protocol

SER       Serial

SERCOS    Serial Real-Time Communications System

SET       Secure Electronic Transaction +

          Software Engineering Technology

.SET      Driver Set (file name extension) [Lotus 1-2-3] [LDC] +

          Image Settings (file name extension) [Paradox]

SETEXT    Structure Enhanced Text [Internet]

SEU       Single Event Upset + Smallest Executable Unit

SF        Sign Flag

SFC       System File Checker

SFD       Start Frame Delimiter

SFDR      Spurious-Free Dynamic Range

SFI         Software Fault Isolation

SFN       Short File Name

SFQL      Structured Full-text Query Language

SFS       System File Server

SFT       System Fault Tolerance

SFX       Self Extracting + Sound Effect(s)

SGA       Shared Global Area

SGCP      Simple Gateway Control Protocol

SGEN      Signal Generator + System Generator

SGDT      Store Global Descriptor Table

SGI       Silicon Graphics, Inc.

SGM       Shaded Graphics Modeling

SGML      Standard Generalized Markup Language

SGR       Set Graphics Rendition

SGRAM     Synchronous Graphics RAM

S/H       Sample and Hold

SHA       Secure Hash Algorithm [NSA]

SHAR      Shell Archive

SHED      Segmented Hypergraphic Editor

SHG       Segmented Hypergraphics

SHL       Shift Logical Left

SHOE      Simple HTML Ontology Extension

SHR       Shift Logical Right

SHTML     Server-Side Include Hypertext Markup Language

S-HTTP    Secure Hypertext Transfer Protocol

SHV       Standard High-Volume

.SHW      Show (file name extension)

SI        Shift-In + Source Index + System Information +

          System Integration

SIC       Standard Industrial Code

SID       Security Identifier + Serial Input Data +

          Station Identification [AT&T] +

          Symbolic Interactive Debugger + System ID

SIDF      System Independent Data Format

SIDH      System Identification for Home Systems

SIDT      Store Interrupt Descriptor Table

SIFT      Stanford Information Filtering Tool

SIG       Special Interest Group

SIGCAT    Special Interest Group on CD-ROM Applications

          and Technology

SIM       Simulator + Subscriber Identity Module

SIMD      Single Instruction, Multiple Data-stream (processor)

SIMM      Single In-line Memory Module

SIMTEL    Simulation and Teleprocessing

SIMULA    Simulation (language)

SIO       Serial Input/Output (communications driver)

SIP       Session Initiation Protocol + Single In-line Package

SIPC      Simply Interactive Personal Computer [Microsoft]

SIPO      Serial In, Parallel Out

SIPP      Single In-line Pin Package

SIR       Serial Infrared [Hewlett-Packard]

SIRDS     Single-Image Random Dot Stereogram

SISL       System Interrupt Steering Logic

SISNET   Signal In Space Through The Internet

SI/SO     Serial In/Serial Out + Shift In/Shift Out

SIT       Special Information Tones

.SIT      Stuff-It (compressed file name extension) [Macintosh]

SIU       System Interface Unit

SIV         System Integrity Verifier

SKIP      Simple Key-Management for Internet Protocols [Sun]

SKU#      Stock Keeping Unit Number

SLA       Service Level Agreement

SLB        Static Load Balancing

SLC       Subscriber Line Concentrator

SLD        Second-Level Domain (name)

SLDT      Store Local Descriptor Table

SLED      Single Large Expensive Disk

SLIC      System Level Integration Circuit +

          System Licensed Internal Code [IBM]

SLIM      Structured Language for Internet Markup

SLIP      Serial Line Interface Protocol

SLM       Spatial Light Modulator

SLMR      Silly Little Mail Reader

SLOSH     Sea, Lake and Overland Surge from Hurricane (program)

SLOT      Scanned Laser Output Terminal

SLP       Service Location Protocol

SLR        Single Lens Reflex

SLSI      Super Large-Scale Integration

SLSS      Systems Library Subscription Service [IBM]

SLU       Spoken Language Understanding

SM        Set Mode + Shared Memory

SMA        Software Migration Assistant [IBM]

SMART     Self-Monitoring Analysis and Reporting Technology

SMB       Server Message Block (protocol) [MII]

SMD       Surface Mounted Device

SMDR      Station Message Detail Recording

SMDS      Switched Multimedia/Multi-Megabit Data Service

SMF       Single Mode Fiber + System Manager Facility [Compaq]

SMI       System Management Interrupt [Intel]

SMIF      Standard Mechanical Interface

SMIL      Synchronized Multimedia Integration Language

S-MIME    Secure MIME

SMIT      System Management Interface Tool [IBM]

SMK       Software Migration Kit [Microsoft]

SML       Standard Meta Language

SMM       System Management Mode [Intel]

SMOBC     Solder Mask Over Bare Copper

SMP       Simple Management Protocol + Symbolic Manipulation

          Program + Symmetrical Multi-Processing +

          Symmetric Multiprocessor

.SMP      Sample (file name extension)

SMPC      Shared Memory Parallel Computer

SMPS      Switching Mode Power Supply

SMRAM     System Management Random Access Memory

SMS       Short Message Service [Sprint] +

              Small Messaging System +

          Storage Management Services [NetWare] +

          Storage Management Subsystem/System +

          Systems Management Server [Microsoft]

SMSW      Store Machine Status Word

SMT       Station Management (protocol) +

          Surface-Mount Technology

SMTP      Simple Mail Transfer Protocol

SMU       System Management Utility

SN        Serial Number

S/N       Signal-to-Noise (Ratio)

SNA       Systems Network Architecture [IBM]

SNAP      Sub-Network Access Protocol +

          Sub-Network Attachment Point

SNAPI     Structured N-Dimensional Application Program

              Interface [Oracle]

SND       Sound

SNEWS     Secure News Server [Internet]

SNMP      Simple Network Management Protocol

SNOBOL    String Oriented Symbolic Language (Programming Language)

SNP       Serial Number/Password [Omen Technology]

SNR       Signal-to-Noise Ratio

SOA       Start of Authority

SOAP      Simple Object Access Protocol

SOC       System On a Chip

SOC.      Social Issues [USENET Newsgroup Category]

SOCKS     Socket Secure (server) [Internet]

SO-DIMM   Small Outline DIMM

SOE       Standard Operating Environment

SOH       Start of Header

SOHO      Small Office/Home Office

SOI        Silicon-On-Insulator [IBM]

SOJ        Small-Outline J-Lead

SOL       Simulation Oriented Language

SOM       Start of Message + System Object Model [IBM]

SONAR    Sound Navigation and Ranging

SONET     Synchronous Optical Network

SOP       Small Outline Package + Standard Operating Procedures

SOS       Silicon On Sapphire + Sophisticated Operating System +

          Standards and Open Systems

SOTA      State Of The Art

SOX       Sound Exchange

SP        Service Pack [IBM] + Stack Pointer + System Product

SPA       Secure Password Authentication [Microsoft] +

          Software Publishers Association

SPAN      Space Physics Analysis Network

SPAP      Shiva Password Authentification Protocol

SPARC     Scalable Processor Architecture +

          Sun's Palo Alto Research Center

SPC       Small Peripheral Controller + Statistical Process Control

SPCL      Spectrum Cellular Corporation

SPCS      Stored Program Controlled Switch

SPD       Serial Presence Detect

SPEC      Systems Performance Evaluation Cooperative

SPF       Shortest Path First + System Programming Facility

SPGA      Staggered Pin-Grid Array

SPI       Security Parameters Index + Service Provider Interface +

          SCSI Parallel Interface + Stateful Packet Inspection

.SPI        Spool (file name extension)

SPID      Service Profile/Provider Identifier

SPIKE     Science Planning Intelligent Knowledge-Based

          Environment [STScI]

SPIRES    Stanford Public Information Retrieval System

          [Stanford University]

SPL       Spooler + System Programming Language [HP]

.SPL      Spell Checker (file name extension)

SPLD      Simple Programmable Logic Device

SPM       System Performance Monitor [IBM]

SPOOL     Simultaneous Peripheral Operations On Line

SPOT      Shared Product Object Tree [IBM]

SPP       Sequenced Packet Protocol + Standard Printer Port

SPPS      Scalable Power Parallel System [IBM]

SPR       Special Purpose Register +

          Statistical Pattern Recognition +

          Symmetrical Phase Recording

SPREAD  * Systems Programming, Research, Engineering

          and Development [IBM]

SPS       Secure Packet Shield + Shock Protection System +

          Standby Power System

SPSS      Statistical Package for the Social Sciences

SPT       Sectors Per Track

SPX       Sequenced Packet Exchange [Novell]

SQ        Squeezed (files)

SQE       Signal Quality Error (test)

SQL/DS    Structured Query Language/Data System [IBM]

SQOS      Secure Quality Of Service

SQRT      Square Root

SR        Shift Register

SRAM      Shadow Random Access Memory +

          Static Random Access Memory

SRAPI     Speech Recognition API

SRB       Source-Route Bridge

SRC        System Resource Conroller

.SRC      Source (file name extension)

SRD       Screen Reader System

SRDRAM    Self-Refreshed DRAM

SRGB      Sustained RGB (values)

SRM       Security Reference Monitor

SRO       Sharable and Read Only

SRP       Suggested Retail Price

.SRP      Script (file name extension)

SRPI      Server-Requester Programming Interface

SRQ       Service Request

SRR       Serially Reusable Resource

SRS       Sound Retrieval System

SS        Stack Segment + Single Sided + Seconds

SS7        Signaling System 7 [Bellcore]

SSA       Serial Storage Architecture

SSAD      Structured System Analysis and Design

SSAP      Source Service Access Point

SSCP      Systems Service Control Point [IBM]

SSD       Solid State Disk

SSEC    * Selective Sequence Electronic Calculator [IBM]

SSGA      System Support Gate Array

SSH       Secure Shell (protocol)

SSI       Server Side Includes + Single System Image +

          Small Scale Integration

SSL       Secure Sockets Layer

SSO        Single Sign On

SSPI      Security Service Provider Interface [Microsoft]

SSRP      Simple Server Redundancy Protocol [Cisco]

SST       Spread-Spectrum Technology +

          Systems Services and Technology

STA       Spanning Tree Algorithm

STAR      Self Defining Text Archival

STB       Strobe

STC       Set Carry Flag

STD       Set Direction Flag + Standard

STDA      StreetTalk Directory Assistance [Banyan]

STDAUX    Standard Auxilary

STDERR    Standard Error

STDIN     Standard Input

STDIO.H   Standard Input/Output Header [C Programming Language]

STDM      Statistical Time Division Multiplexer

STDOUT    Standard Output

STDPRN    Standard Printer

STEP      Standard for Exchange of Product

.STF      Structured File (file name extension) [Lotus Agenda]

STI       Set Interrupt Flag

S/TK      Sectors Per Track

STL       Standard Template Library

STM        Scanning Tunneling Microscope

STN       Super-Twist Nematic

.STORE    Businesses Offering Goods (Domain Name) [Internet]

STOS      Store String

STP       Secure Transfer Protocol + Shielded Twisted Pair (cable) +

          Signal Transfer Point +

          Synchronized Transaction Processing

STR       Store Task Register + Synchronous Transmitter Receiver

STRESS    Structural Engineering System Solver (Programming

          Language)

STRUDL    Structural Design Language (Programming Language)

STScI     Space Telescope Science Institute

STT       Secure Transaction Technology [Microsoft]

STX       Start of Text

.STY      Style (file name extension) [Ventura, Word, WordPerfect]

SUB       Subroutine + Substitute + Subtract

SUN       Sun Microsystems, Inc.

.SUP      Supplemental Dictionary (file name extension)

          [WordPerfect]

SVC       Switched Virtual Circuit

SVF       Simple Vector Format

SVG       Scalable Vector Graphics

SVGA      Super Video Graphics Array

S-VHS     Super VHS

SVM       System Virtual Machine [Microsoft] +

              System Volume Management

SVN       Switched Virtual Network [IBM]

SVR       Server

SVR#      System V Release Number [AT&T]

S/W       Software

SWAC    * Mobile version of SEAC, built for deployment to White

          Sands, and named Standards Western Automatic Calculator

SWAIS     Simple Wide Area Information Server [Internet]

SWAP      Shared Wireless Access Protocol

SWIG      Simplified Wrapper and Interface Generator

SWISH     Simple Web Indexing System for Humans

SWP       Simple Web Printing

.SWP      Swap (file name extension)

.SYL      Syllabus (file name extension)

SYLK      Symbolic Link

.SYM      Symbols (file name extension)

.SYN      Synonym (file name extension)

SYNC      Synchronous

SYS       System

.SYS      System Configuration (file name extension) +

          System Device Driver (file name extension)

SYSADMIN  System Administrator

SYSGEN    System Generator

SYSLOG    System Log

SYSMOD    System Modification

SYSOP     System Operator

SYSREQ    System Request

SZ        Send ZModem [Unix]