TT, Tt or tt has more than one meaning:

• Atari TT, a computer based on the Motorola 68030 CPU.
• Audi TT, an automobile produced by Audi.
• Table Tennis
• TT scale (Table Top scale), a niche model railroading scale.
• Teen Titans (comics), a DC Comics superhero team. See also Teen Titans (TV series).
• teetotal (or T-total), the practice and promotion of complete abstinence from alcoholic beverages.
• Terrestrial Time
• Text telephone
• Therapeutic Touch, an alternative medicine practice.
• Thermaltake (uses "Tt" as their logo)
• Three Towns, a beer brand.
• Tidningarnas Telegrambyrå, a Swedish news agency.
• Timed Text, a W3C format for captioning, subtitling timed text media on the Web.
• Time Team, a popular archaeological British TV program on Channel 4.
• Today Tonight, an australian current affairs show.
• A race in motorcycle racing, TT meaning Tourist Trophy:
  • Isle of Man TT
  • Dutch TT
• Tourist Trophy (video game), a PlayStation 2 video game by Polyphony Digital.

• Transport Tycoon, a computer game by Chris Sawyer.
• tritone, a musical interval that spans three whole tones.
• Trouble Ticket
• TrueType, a font format.
• TT earthing system, is one where the customer's earth has no connection to the transformer neutral terminal.

• TT is the IATA code for "Air Lithuania".
• TT is the ISO 3166-1 alpha-2 Country code for "Trinidad and Tobago".
• TT is the AAR reporting mark of "Toledo Terminal Railroad".
• tt is the ISO 639 language code for the "Tatar language".

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