Text message

From Memory Alpha, the free Star Trek reference

A text message (or TEXT MSG) is a typed communication sent from one computer panel to another. Starfleet ships enable this ability, which is sometimes used when verbal contact could be dangerous, or is impossible.

In 2153, Captain Jonathan Archer needed to make the crew believe he had died when a group of Triannon religious extremists took control of the ship. He contacted Dr. Phlox in sickbay from a access corridor at the bottom of the ship to ask how to disable the explosives the extremists had in their body. (ENT: "Chosen Realm")

In 2378, after Shinzon had destroyed the viewscreen of the USS Enterprise-E, Captain Jean-Luc Picard hailed him and sent a text message to Deanna Troi, who was at the helm, to ram the Scimitar on his command. (Star Trek Nemesis)

The timecodes used in Star Trek Nemesis start with "STN", after the movie's title.

[edit] Background

In the commentary by Mike Okuda on Star Trek Nemesis, he notes that it remains unknown how characters throughout Star Trek history type messages without anything even closely resembling a QWERTY-like keyboard system, especially Captain Picard's chair, which only has a few buttons on it. However, in the 21st century, millions of people have indeed learned to type with only the numeric keypad of a cellular phone, meaning Star Trek has once again foreseen what was to come in our present society.