| T1 | T-One - Carrier Signal (communications) | - | Human Genome |
| T3 | T-Three - Carrier Signal (communications) | - | Human Genome |
| TA | Terminal Adapter | - | Human Genome |
| TANSTAAFL | There Ain't No Such Thing As A Free Lunch | - | Human Genome |
| TAPI | Telephony Application Programming Interface | - | Human Genome |
| TCP/IP | Transmission / Transport Control Protocol/Internet Protocol | - | Human Genome |
| TDM | Time Division Multiplexing | - | Human Genome |
| TDMA | Time Division Multiple Access | - | Human Genome |
| TFT | Thin Film Transistor | - | Human Genome |
| TFTP | Trivial File Transfer Protocol | - | Human Genome |
| TIA | Thanks In Advance | - | Human Genome |
| TIFF | Tagged Image File Format | - | Human Genome |
| TIGA | Texas Instruments Graphics Architecture | - | Human Genome |
| TLD | Top-Level Domain | - | Human Genome |
| TOPS | Transparent Operating System | - | Human Genome |
| TPI | Tracks Per Inch | - | Human Genome |
| TRAM | Transactional RAM | - | Human Genome |
| TSAPI | Telephony Service API | - | Human Genome |
| TSR | Terminate-and-Stay-Resident | - | Human Genome |
| TTF | True Type Font | - | Human Genome |
| TTL | Transistor-Transistor Logic | - | Human Genome |
| TWAIN | Technology Without An Interesting Name | - | Human Genome |
| TWIP | Twentieth Of A Point | - | Human Genome |
| TACACS | Terminal Access Controller Access Control System
| - | Human Genome |
| TALS | time division multiplexing (TDM) access line service
| - | Human Genome |
| TAP | telocator alphanumeric protocol
| - | Human Genome |
| TAPS | ticket analysis performance system
| - | Human Genome |
| TAS | Traffic Analysis Service
| - | Human Genome |
| TB&R | tape backup and restore
| - | Human Genome |
| TCB | technical control bridge
| - | Human Genome |
| TCC | Transition Control Center
| - | Human Genome |
| TCIF | Telecommunications Industry Forum
| - | Human Genome |
| TCM | traffic capacity management
| - | Human Genome |
| TCO | TSP Coordinator's Office
| - | Human Genome |
| TCOS | traveling classmark
| - | Human Genome |
| TCP | transmission control protocol
| - | Human Genome |
| TD | transport demultiplexing
| - | Human Genome |
| TDD | Telecommunications Device for the Deaf
| - | Human Genome |
| TDD/TTY | Telecommunications Device for the Deaf/Teletypewriter
| - | Human Genome |
| TE | traffic engineering
| - | Human Genome |
| TELNET | Terminal-remote Host Protocol Program
| - | Human Genome |
| TE-MAR | traffic engineering-maximum allocated resources
| - | Human Genome |
| TESP | telecommunications electric service priority
| - | Human Genome |
| TFMM | toll-free multimedia
| - | Human Genome |
| TFS | Toll-Free Service
| - | Human Genome |
| TIC | Trusted Internet Connections
| - | Human Genome |
| TICAP | Transport Internet Connection Access Provider
| - | Human Genome |
| TIMO | Transition, Implementation, Migration Office
| - | Human Genome |
| TIN | Taxpayer Identification Number
| - | Human Genome |
| TKIP | temporal key integrity protocol
| - | Human Genome |
| TLS | transport layer security
| - | Human Genome |
| TMF | TeleManagement Forum
| - | Human Genome |
| TMN | total management network
| - | Human Genome |
| TMO | Technology Management Office
| - | Human Genome |
| TMP | Transition Management Plan
| - | Human Genome |
| TMS | technical and management support
| - | Human Genome |
| Tn | trunk level n
| - | Human Genome |
| TNPP | telocator network paging protocol
| - | Human Genome |
| TO | task order
| - | Human Genome |
| TOD | time of the day
| - | Human Genome |
| TOF | technical order form
| - | Human Genome |
| TOH | transport overhead
| - | Human Genome |
| TP | Transition Plan
| - | Human Genome |
| TP(Billing) | FTS Non-Itemized Purchase Order
| - | Human Genome |
| TPA | TP Agreement
| - | Human Genome |
| TPS | Two-Way Paging Service
| - | Human Genome |
| TRACS | Total Router Access Configuration System
| - | Human Genome |
| TRM | Technical Reference Model
| - | Human Genome |
| TS | Telecommunications Services, Trade Study
| - | Human Genome |
| TSA | Transportation Security Administration, Time Slot Alignment
| - | Human Genome |
| TSAA | terminating switched access arrangement
| - | Human Genome |
| TS/SCI | Top Secret/Sensitive Compartmented Information
| - | Human Genome |
| TSG | timing signal generator
| - | Human Genome |
| TSI | Time Slot Interchange
| - | Human Genome |
| TSNOW | transport service now
| - | Human Genome |
| TSP | telecommunications service priority
| - | Human Genome |
| TSS | telecommunications service sector
| - | Human Genome |
| TTR | Time to Restore
| - | Human Genome |
| TTS | text to speech
| - | Human Genome |
| TUI | telephony user interface
| - | Human Genome |
| TWS | Teleworking Services
| - | Human Genome |
