T Traveler 
T1 1.544Mbps (Telefonia), um dos sistemas de sinais básicos 24x64Kb
T3 45Mbps (eq 28 T1 channels) (Telefonia)
TA Teaching Assistant
TAC Tactical Air Command (veja também SAC)
TAC Terminal Access Controller [ARPANET/MILNET] (substituído por TIP)
TACACS Terminal Access Controller Access Control System [ARPANET/MILNET]
TACCS Tactical Army Combat service support Computer System
TAE Transportable Applications Environment
TAL Trans-Atlantic Abort Landing [NASA, Lançamento]
TAL Transatlantic Abort Landing (Shuttle abort plan) (Espacial)
TANSTAAFL There Ain't No Such Thing As A Free Lunch
TAR Tape ARchiver
TASI Time Assign{ment,ed} Speech Interpolation (Telefonia)
TAU Thousand Astronomical Units (Espacial)
TB TuBerculosis
TBA To Be Announced
TBD To Be Determined
TBD To Be Done
TC Teachers College
TCA Terminal Controlled Airspace
TCP Transmission Control Protocol
TCP/IP Transmission Control Protocol/Internet Protocol
TCS Thermal Control System (Espacial)
TCSEC Trusted Computer System Evaluation Criteria (livro laranja)
TCT To Challenge Tomorrow
TD Tardive Dyskinesia
TD TouchDown
TD Treasury Department
TDCC Transportation Data Coordinating Committee
TDE Transition Diagram Editor
TDI Trusted Database Interpretation
TDM Time-Division Multiplexer
TDR Time Domain Reflectometer
TDRS Tracking and Data Relay Satellite (Espacial)
TDRSS Tracking and Data Relay Satellite System (Espacial)
TDY Temporary DutY
TECO Tape Editor and COrrector
TECO Text Editor and COrrector
TEFLON polyTEtraFLuOrethyleNe
TES Thermal Emission Spectrometer (em Observador de Marte) (Espacial)
TFP Tops Filing Protocol
TFS Translucent File System
TFT The Fantasy Trip
TFT Thin Film Transistor
TG Thieves' Guild
TGV Tres Grande Vitesse (French, Very High Speed) (Rede ferroviária)
TGV Two Guys and a VAX (humorous variant) (nome de companhia)
THIEF THief Isn't Even Fine
THIEF This Here Isn't Even Fine
THOR Tandy High-intensity Optical Recording
TI Texas Instruments
TIA Thanks In Advance (Jargão usado na Net)
TIA Transient Ischemic Attack
TIC TermInfo Compiler
TID Ter In Die (three times a day)
TID Transaction ID
TIFF Tag Image File Format
TIP Terminal Interface Processor [ARPANET/MILNET] (substituído por TAC)
TIS Trusted Information Systems (nome de companhia)
TISN Tokyo International Science Network (Japão)
TKO Technical Knock Out 
TL Total Loss
TLA Three Letter Acronym
TLC Tender Loving Care
TLI Transort-Level Interface
TM TradeMark
TMA Tycho Magnetic Anomaly (filme 2001)
TMAC Treasury department's Multiuser Acquisition Contract
TMIS Telecommunications Management Information System
TMO Telephone Money Order
TMP The Morrow Project
TMRC Tech Model Railroad Club [MIT]
TMRC Transportation Modeling Research Center 
TN Tennessee
TN Twisted Nematic
TNC Threaded Neill Concelman (conector electronico] (veja também BNC)
TNF Tumor Necrosis Factor [Biologia, Medicina]
TNP Tech Nickel Plate (Rede ferroviária) [TMRC]
TNT TriNitro Toluene
TO Telegraph Office
TO Turn Over
TODS Transactions on Database Systems (ACM)
TOMS Total Ozone Mapping Spectrometer (Espacial)
TOMS Transactions on Mathematical Software (ACM)
TOOIS Transactions on Office Information Systems (ACM)
TOP Technical Office Protocol
TOPLAS Transactions on Programming Languages and Systems (ACM)
TOPS Traffic Operator Position System (Telefonia)
TOPSMP Traffic Operator Position System Multipurpose (Telefonia)
TORES Text ORiented Editing System
TOS Transfer Orbit Stage (Espacial)
TOW Tube launched, Optically tracked, and Wire guided
TOY Time Of Year (clock)
TP Transaction Processing
TP Transport Protocol (ISO/CCITT Transport Services (TP0-TP4); like TCP)
TP4 Transport Protocol, class 4 [ISO]
TPC The Phone Company (from classic movie: _The President's Analyst_)
TPI Tracks Per Inch
TPO Traveling Post Office
TPP TetraarylPorPhyrin
TPS Technical Publishing Software
TPS TeleProcessing Services
TPS Thermal Protection System (Espacial)
TR Tech Report (último do LCS (q.v.), talvez outros)
TR Technical Reference (Telefonia)
TRG Tip and Ring Ground (teste) (Telefonia)
TROFF Text RunOFF, text formatter
TRUSIX TRUSted unIX
TRW Thompson, Ramo, and Woolridge
TS Top Secret
TSAP Transport Service Access Point [OSI, Networking]
TSD Total System Design
TSP Teleprocessing Services Program
TSP Thrift Savings Plan
TSP Time Synchronization Protocol
TSP TriSodium Phosphate
TSR TSR (fortuna das companhias que construíram Dungeons & Dragons)
TSS Tethered Satellite System (Espacial)
TSTO Two Stage to Orbit (Espacial)
T&T Tunnels & Trolls
TTFN Tah Tah, For Now
TTL Transistor Transistor Logic
TTMA Tennessee Tech Microcomputer Association
TTU Tennessee Technological University
TTY TeleTYpe
TUNIS Toronto UNIversity System
TV TeleVision
TVA Tennessee Valley Authority
TW Thieves' World
TWA Trans World Airlines (nome de companhia)
TWB Terrestrial WideBand [Networking, DARPA]
TWIMC To Whom It May Concern
TWT Traveling Wave Tube
TWX TeletypeWriter eXchange
TX Texas
Tx Transmit
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